But I Can't Be Pregnant

"Listen to me, getting pregnant has a certain physical requirement that I have not fulfilled in a very long time!"

- Xena: Warrior Princess to her doctor.

A character finds herself (or himself) - or he finds his female partner - pregnant, after being declared infertile by doctors. Also occurs when the prospective parents are of different species (comics, sci-fi) or when the parents are already of grandparenting age. Often, the male will accuse his partner of cheating, only to eat crow later when medical tests (either on himself or a paternity test) proves he's the father. In television, this trope is often the result of an actress' real-life pregnancy. A favored trope of soap operas.

See also: But We Used a Condom, Law of Inverse Fertility, Surprise Pregnancy.

Anime and Manga

 * In the last issue of the Hentai Boys Empire, finds out she's pregnant.

Comic Books

 * In The Great Ten, this is part of Mother of Champions' backstory. She was incredulous when she discovered she was pregnant, for a number of reasons - one, because her husband had recently left her due to her inability to conceive, and two, because she was visibly pregnant the day after her drunken one-night stand. As it turns out, she'd developed a special, ahem, gift, giving birth to twenty five boys days later.

Film
"Elektra Luxx: I can't be pregnant. Doctor: Are you a virgin? Elektra Luxx: No. Doctor: Then you can be pregnant."
 * Baby Mama:.
 * The Czech films Divided We Fall and Little Otik both in a sense follow this trope and subvert it. Both couples in both films are infertile (in both cases ), and both couples get around nature to create a child, either a real one -   (Divided We Fall) or a monstrous one,   (Little Otik). In each case, it is the neighbours who are forced to suspend their disbelief at the "fact" the wife is pregnant, rather than the couple themselves, who collude in trying to bring a child into the world.
 * Dogma. Despite having been infertile for apparently years, at the end of the movie Bethany is told by Metatron that she's miraculously pregnant (necessary because she's the Last Scion - need to keep that bloodline going). It's heavily implied that because she's a descendant of the Virgin Mary her pregnancy is similar to Mary's conception of Jesus.
 * Extant: The story revolves around astronaut Molly Woods, who returns home to her family inexplicably pregnant after 13 months in outer space during her mission.
 * A really interesting example in the French-Canadian film Familia: teenage Marguerite learns she is pregnant, but she's never had sex. Though not really religious, she begins to wonder if this is a second virgin birth.
 * In Hellboy 2: The Golden Army,  being physically impossible for several reasons.
 * Prometheus uses this in the most horrifying way imaginable:.
 * Starman: After he and Jenny made love on the train Starman proclaims "I gave you a baby tonight." Jenny says that this is impossible because she is incapable of having a child. Starman explains that he used his powers to alleviate this.
 * Once Bella becomes pregnant in The Twilight Saga: Breaking Dawn Edward asks if it's even possible as he is a vampire and Bella is a human.
 * Village of the Damned (from the sci-fi novel The Midwich Cuckoos by John Wyndham). Aliens impregnate every woman of child-bearing age in a small English town. Initial reactions range from joy (from a previously childless couple) to suspicion (from a husband who's been away at sea) to the above incredulous reaction from a teenage virgin.
 * In the film Women in Trouble, porn starlet Elektra Luxx is informed by her doctor that she is now gravid, and she responds by quoting this trope's name almost verbatim:

Literature

 * Examples from The Bible: Abraham and Sarah in the book of Genesis, where Sarah didn't believe it at first when Abaraham revealed that God had told her she'd be pregnant, as she was past childbearing age. Subverted with the Virgin Mary in the synoptic Gospels, since she knew beforehand that she'd be the mother of Christ, but Joseph suspects her of infidelity until an angel shows up to personally set him straight. There's also the infertility example with Elizabeth and Zechariah, parents of John the Baptist. Here it's Zechariah who utters the "but that's impossible" line. He's struck with dumbness until the child is born as punishment.
 * Janette Oke's Prairie Romance series, starting with Love Comes Softly, develops a huge clan of children under the care and guidance of main character Marty and her husband (Davis?). Several books down the line, after Oke had "officially" finished the series, the series starts back up with Marty realizing that she is again pregnant... and thinking it beyond embarrassing that her daughter will be younger than several of her grandchildren.
 * In the The Time Traveler's Wife Clare gets pregnant.
 * In Monsieur Malaussène by Daniel Pennac, a nun whose chastity is beyond doubt becomes pregnant. There are a number of pregnancies in this novel; this being Pennac, they're not straightforward.
 * In Heinrich von Kleist's 1808 novella, The Marquise of O, the titular Marquise finds herself mysteriously pregnant and places an announcement in the newspaper demanding the unknown father of her child identify himself so she can marry him. It turns out
 * In the Alien Nation Expanded Universe novel Cross of Blood, Tectonese Cathy Frankel turned out to be pregnant. This came as a shock to her human boyfriend Detective Matt Sikes, because among the Tectonese, pregnancy can only occur when the female is inseminated by a "third" gender or "catalyst." It is later discovered that, due to their genetic adaptability, a Human/Tectonese pairing can result in pregnancy.
 * In John Varley's Titan, the female members of the spaceship crew all turn out to be pregnant after they're released into Gaea's interior. This trope especially applies to April Polo, a lesbian who's never had sex with a man.
 * Arguably subverted by the fact that, unlikely as these conceptions might be, none of the characters propose any alternative explanation for their failure to menstruate (e.g. wondering if they'd been sterilized rather than impregnated). There's little actual denial, just dismay.
 * Later in the series, the trope applies to both of Robin's pregnancies.
 * There is a Swedish short story in which a man who thinks he's sterile is in the habit of killing his girlfriends when they become pregnant because he can't handle the fact that they have apparently cheated on him. It isn't until after several murders that he finds out it's actually his twin brother who's sterile, not him.
 * In Jacqueline Carrey's Santa Olivia, a genetically modified man overhears scientists discussing his apparent sterility. After he escapes, he meets a woman and they have sex. Lo and behold...she gets pregnant with his daughter.
 * In the Deverry novels, Rhys' first wife is cast aside for being barren. Her mother-in-law arranges for her to remarry to a widower with several children from a previous marriage (and as such would not need to care as to whether or not his new wife could provide an heir). Shortly afterwords, she surprises everyone by getting pregnant, and later gives birth to a healthy boy. It seems that she wasn't the sterile one in her previous marriage...
 * In Robert A. Heinlein's Friday, the titular protagonist is sterile by permanent (but reversible) surgery, and is therefore extremely surprised to discover that she's expecting during a long interstellar voyage. It turns out that

Live Action TV
"The Worthless Peons: I want my baby-back (baby-back) baby-back (baby-back) baby-back (baby-back) baby-back, I want my baby-back (baby-back)... Doctor: Dear God. When do they say "ribs"? Dr. Cox: Never. They never say "ribs.""
 * Charlotte Ross' real life pregnancy was written into the 11th season of NYPD Blue, despite her character's being established as infertile due to complications from a teen pregnancy. This was a rather mild retcon, revealed as her doctors telling her it would be almost impossible for her to get pregnant.
 * Delenn's pregnancy in Babylon 5 was thought to be impossible, due to her hybrid biology. Word of God states that Sheridan was aware a child was possible, but wasn't sure if the future had been changed, and, if it had been changed, if the circumstances that led to the child were still possible. Time travel is tricky that way.
 * Subverted in The Golden Girls, where Blanche's suspected pregnancy turns out to be menopause.
 * So did Kitty from That '70s Show.
 * Same with Helen Rosenthal on St/Elsewhere
 * This version was inverted on Dharma and Greg, when Abby (mother of an adult daughter) thought she was entering menopause, and turned out to be pregnant.
 * The same inversion (what was thought to be menopause turns out to be pregnancy) appears in Father Of The Bride 2.
 * Murphy Brown does it both ways: she thinks her pregnancy is menopause, then when she does go through menopause she thinks she's pregnant.
 * An episode of Sisters had oldest sister Alex thinking she was pregnant because her period was late and that "the last time that happened, we named her (her daughter) Reed!." Of course, it turned out to be menopause.
 * On Life Goes On, Libby believed she was experiencing symptoms of early menopause, only to find she was pregnant—and very worried, as she already had a Down's Syndrome child and knew this and her advanced age made it likely that she'd have another (she didn't).
 * Season two of Too Close For Comfort focused on Muriel's pregnancy, Henry and Muriel having been established as in their late 40s/early 50s, with two adult children already.
 * Soap opera example: All My Children's Opal Gardner (who'd already had three adult children) found herself pregnant (after, of course, thinking she was starting menopause) by new husband (and resident Scrooge) Palmer Cortlandt. Palmer immediately accused her of infidelity because he'd been rendered sterile years ago "by a polo accident." Medical tests later proved that his plumbing still worked.
 * Also with the now deceased Courtney on General Hospital. She became pregnant with Nikolas Cassadine's child miraculously after being rendered barren after a miscarriage with Jason Morgan's child, because of fuzzy medical reasons. It was the same story with Skye Quartermaine, but somehow she managed to conceive and birth a child with Lorenzo Alcazar.
 * In Days of Our Lives, the character Nicole was shot and told that she would never be able to have children due to internal scarring. Lo and behold, a few years later Nicole is impreginated by EJ.
 * In the NBC show Scrubs, Dr. Cox's ex-wife, Jordan, became pregnant (as she was pregnant in real life). Since Dr. Cox had previously gotten a vasectomy, they addressed this - Dr. Cox asked if Jordan cheated on him shortly after she tested pregnant, and later when they told the rest of the staff about her pregnancy, he does a rant where he mentions his vasectomy didn't take. He and Jordan later get revenge on the doctor who performed it.

"House: You're pregnant. Girl: But I can't -- House: Are you a virgin? Girl: No. House: You're pregnant."
 * Gilmore Girls did the same thing with Sookie and Jackson when they wrote in Melissa McCarthy's pregnancy despite having an episode two seasons earlier where Jackson had a vasectomy that he didn't want. They retconned it by having Jackson say he lied about getting it since he hadn't wanted it in the first place, and that he thought Sookie would stay on her birth control pills to keep her skin looking fresh.
 * A different take on it occurred in Xena: Warrior Princess, when Xena was rather shocked to be pregnant - she hadn't had sex (with a man) in ages.
 * The Korean couple (Jin and Sun) in Lost. Jin was sterile before he came to the island, which causes Sun to believe the baby was conceived during her extramarital affair before the plane crash. However, Juliet explains that male sperm count is five times normal on the island, and a sonogram shows that the baby was indeed conceived on the island.
 * A particularly heartbreaking example, as pregnant women tend not to survive their pregnancy on the island—if the baby was conceived before Sun came to the island, she's fine, and if the baby is miraculously her husband's and conceived after their island-inspired reconciliation, she's going to die. She's very happy with the result.
 * Scully in The X-Files got pregnant about four seasons after being diagnosed as infertile. Interestingly, the actress' real-life pregnancy had taken place, and been somewhat clumsily covered with big coats, sitting at desks, etc. about two years before the character was supposedly rendered infertile.
 * Inverted in Friends: Courteney Cox and her husband were trying for a baby, so her character Monica and her husband Chandler started trying for one too. When Cox and David Arquette started having fertility problems, Monica and Chandler started having them too. Ironically, Cox became pregnant in the final season, when Monica and Chandler had already agreed to adopt. Lots of baggy tops towards the end of season 10.
 * Additionally, Ross was once described as a "medical marvel," as his parents' doctor had believed his mother was infertile prior to her pregnancy.
 * On Angel, Connor, the human offspring of a fling between the vampires Angel and Darla. Vampires were canonically stated to be infertile. Darla apparently responds by going on a world tour searching for someone who can tell her what's going on and/or kill the mystically protected child, leaving corpses in her disappointed wake.
 * Sharon Watts in Eastenders believed herself to be infertile after a botched abortion for years until she conceived a baby with her adoptive brother/husband Dennis, who was murdered a couple of episodes later.
 * In Desperate Housewives, Gabby has a miscarriage in the second season and her doctor says she is unable to bear children any longer. By the fifth season, however, thanks to the Time Skip, she has two young daughters. (The "But I can't be pregnant" scene is later shown in a flashback, complete with Gabby slapping the doctor).
 * In House, House confronts a complainy teenage girl on an airplane:

"Neil: But that's impossible! Vyvyan: Yeah, that's what she said! You just can't trust women, can you?"
 * Played with in the episode "Joy to the World," where a woman is pregnant even though she and her fiance are waiting till marriage, and she swears she hasn't cheated. A skeptical House runs a DNA test and returns dumbfounded to tell them that there actually is no father, and the woman is the first ever case of human parthogenesis, an incredible phenomenon... except she's not, she just cheated on her fiance, and he's lying so that they'll be bowled over with elation and gratitude and get him a Christmas present, which he bet Wilson he could get a patient to do.
 * Another episode includes a woman who miscarried a baby, but claimed she couldn't have been pregnant as she hadn't had sex in over a year. Turns out.
 * Star Trek: Voyager. Half-Human Hybrid B'Elanna Torres is surprised when this happens with her human boyfriend Tom Paris, as the odds against a Klingon woman and a human man having children naturally is so high. The actress playing B'Elanna had become pregnant several years earlier, which was hidden by having her Wrench Wench character wear a work smock with tools in the top pocket.
 * Maude in Maude became unexpectedly pregnant at 47 while taking birth control, and later had the very first sitcom abortion.
 * Claudia Black, who played Vala Mal Doran on Stargate SG-1, got pregnant with her first child shortly into fliming for the ninth season. She was reportedly worried about being taken off the show or ruining the plot.. fortunately the creators were already planning a storyline involving her being pregnant. As a result, Vala ended up lost in the Ori's home galaxy for much of Season 9, and when she came back in the last few episodes, was revealed
 * In Red Dwarf Lister sees his future self with twin babies. The question is raised of how this could be possible without a woman on board, and he says it will be fun finding out.
 * Coupling had a pregnancy scare storyline at the end of season 3 - Sally is the one who believes she's at risk and asks the other girls to take a test as well as a control group. She then gets the tests mixed up, so when she finds out one of them is positive, she realises it can be any of them. While they're waiting to go back and buy more tests, reveals that she just found out she's infertile. Towards the end, 's test comes back negative, which results in  assuming it's her, and becoming deeply unhappy since it probably wrecks her chances with . And then  walks in with a positive test.
 * Parodied on The Young Ones, where Vyvyan—who is male—announces he's pregnant:

"Becker: You know what this means... Patient: ...it's a miracle! Becker: Sure, Let's Go with That"
 * Played with in Becker. After performing a fertility test on a male patient, Becker tells his (female) employee that "Your sperm count is higher than his!" Said patient's wife ends up pregnant anyway.


 * In Sugar Rush (TV), Kim's mother Stella becomes pregnant after getting back together with Nathan, even though in the first series she told her lover that he had.
 * In FlashForward, Janis sees in her flash-forward that she is pregnant. She can't believe this as she is a lesbian. Eventually she does become pregnant by.
 * Married... with Children subverted this when a deceased relative's will stipulates that any family member that conceives a new child will get a $500,000 inheritance. Al and Peg naturally go for it, but Peg doesn't want to pregnant. She just wants regular sex, so she secretly takes birth control. Al finds out eventually and gets his revenge by faking Peg's home pregnancy test for a positive result. Peg goes into this mode, but Al twists the knife further by saying another relative beat them to the inheritance and reminds her of everything she went through with Kelly and Bud (morning sickness, weight gain and diaper changes). Peg effectively Goes Mad From the Revelation, while Al is gleeful.

Tabletop Games

 * In the Vampire: The Masquerade supplement Time of Thin Blood, it's revealed that fifteenth-generation vampires can accidentally or intentionally reactivate various bodily functions temporarily—including the reproductive system, enabling them to produce offspring with humans.
 * The Werewolf: The Apocalypse adventure Rage Across the Heavens largely revolves around a werewolf cub born of two supposedly infertile Metis werewolves (the parents are both offspring of two werewolves, rather than one werewolf and either a human or a wolf).
 * Normally, Prometheans are infertile until they finally become human, but one very rare possibility is that they manage to have a baby of their own, whether with a human or another Promethean. The kids turn out both mortal and normal... except that they can sense Azoth and are completely immune to Disquiet.
 * Fetches are infertile as well, being magical constructs. Under certain exceptional circumstances, however, they may produce offspring. Fifty percent chance it's a nightmarish thing of evil, fifty percent chance it's mostly normal but with some sort of Ambiguous Disorder and with blood that poisons the True Fae.

Videogames

 * Played with in Metal Gear Solid 2: Sons of Liberty, when Rose tells Jack she's pregnant but . Also, it's possible she can't be pregnant because . It turns out she is, and, obviously, she does, but the whole of Metal Gear Solid 2: Sons of Liberty was such a Mind Screw that it takes until the fourth game for any of this to be clear.

Webcomics

 * Finally confirmed after nearly four years of hints: In Twokinds, where (as a result of literal Deus Ex Machina) feline Keidrian Flora is pregnant with human Trace's child. Though it's later implied that the real Deus Ex Machina was the lack of such hybrid pregnancies up to now (i.e. Ephemural allowed Flora's pregnancy rather than stopping it.).
 * Hatsuki reacting thusly in Moon Over June is quite understandable given that she does not have sex with men in either her personal or professional life. However when one's... costars... do not clean themselves up/off/out well enough between scenes then such things can happen.
 * Gene Catlow: This is Cotton's reaction when Tatavania tells him she's pregnant. They had never (physically) made love. Cotton's shock lasts all of five seconds, since they decide their bond via Sight Of The Soul is so powerful, their spiritual humping spilled over into the physical world.

Web Original

 * Paradise: In "Reverberations," a story in this setting, a gender-bent character's unexpected pregnancy causes the Masquerade concealing her new gender from friends and family members to fail.
 * Happens a couple of times in Chakona Space due to meddlesome Rakshani fertility deities.

Western Animation

 * Inverted in South Park, where Ms. Garrison assumes that not having a period after having a lot of random, unprotected sex with random men has made her pregnant (she becomes excited because now she can have an abortion). The doctor informs her that as a transexual, she lacks both a uterus and eggs, and therefore is not physically capable of getting pregnant. Ms. Garrison claims the doctor is a bigot.

Real Life

 * Comes up every now and again when Maury does paternity tests—a man who has been declared infertile/had a vasectomy will demand a paternity test on his girlfriend/wife's child, for obvious reasons. A surprisingly large percentage turn out to be the child's father after all.
 * A ridiculous example was this teenage girl who brought this guy onto the Sally Jesse Raphael show because she was convinced he was the father, because apparently he was the only guy she'd slept with. He was relieved when it turned out not to be his child, but she was still really confused. Turns out that she'd been regularly sleeping with her step-brother, and she was under the impression that she couldn't get pregnant by him. He was the father, of course.
 * Subverted in the Strikeforce Mixed Martial Arts promotion before the highly-publicized August 2009 fight between Gina "Conviction" Carano and Christine "Cyborg" Santos to crown American MMA's first female 145-lb champion. Santos' management called Strikeforce CEO Scott Coker the day before the fight and told him that the California State Athletic Comission had just informed them that Santos was pregnant and wouldn't be allowed to fight. They called back a few minutes later and informed a panicking Coker that it was just a joke.
 * Truth in Television. Infertility is not the same as sterility and a sufficiently fertile female partner can compensate for a low sperm count. There have been recorded incidences where men with vasectomies have fathered children. Same thing for females who have had an operation. And at least one particularly fertile couple where both had the operation, and a child was produced anyway.
 * There are also cases where a couple fails to conceive despite fertility treatments, but end up pregnant soon after "giving up". It is said that stress can be a factor to infertility some times, and "trying" to conceive may make matters worse.
 * Denial is a big issue for some featured on (The Customer is) Not Always Right.
 * Horrifying variation from France, where "at least five" women were in such a state of denial/trauma over their pregnancies that they killed the newborns and hid the bodies—in some cases over a half-dozen times—and forgot it ever happened. The woman in the latest case had had a difficult pregnancy and was too scared to go to the doctor, and her husband didn't notice anything unusual (eight times) because she was chubby. The doctor quoted in the report feels that "pregnancy denial" is a legitimate psychological problem and that it's foolish to think it's exclusively French.
 * There was a similar example in the summer of 1997 in New Jersey, where a young woman named Melissa Drexler, dubbed "The Prom Mom" slipped out of her prom, gave birth in the bathroom, strangled the baby and left his body in the garbage, then returned to the prom to eat and dance. No one ever remembered her even looking as though she were pregnant, not even a girlfriend who had been trying on dresses with her only weeks before. It's believed that fear of her parents' anger led her to be in denial over her pregnancy.
 * There was a documentary on women having affairs on Discovery Health Channel which had an Asian couple who had trouble having children. Eventually, she got pregnant. Unfortunately, she neglected to tell her husband that it was another man's child. He found out when she had an African-American baby.
 * The TLC show I Didn't Know I Was Pregnant is dedicated to real life examples of this, usually either couples who thought they couldn't have kids, women who had their tubes tied, or party girls who didn't want to get pregnant.
 * Or, in rare cases, where women menstruated throughout their whole pregnancy, didn't gain weight, and didn't feel the baby moving. It's one in a million, but it can happen.