Movies like Knocked Up and Juno make it seem like getting pregnant is NBD, but the truth is that it can be a little tricky, particularly if you're uninformed. Even if motherhood seems light years away (kids—lolz), it's never too soon to get informed. Here's what you need to know now about getting pregnant:
1. This is how you get pregnant: About 14 days before your next period is scheduled to arrive, your left or right ovary (which switch off every cycle) releases an egg in a process known as ovulation, explains Maria Sophocles, board-certified gynecologist and medical director of Women's Health Care, a private practice in Princeton, New Jersey, and a mother of four who's delivered more than 8,000 babies. The egg travels down the fallopian tube and waits for sperm to show up. During penetrative vaginal sex involving ejaculation, millions of sperm enter the vagina and travel through the cervix into your uterus. There, they pick a path: The left or right fallopian tube. The sperm that pick the tube where that month's egg resides get all up in there, burrowing into the egg. To become an embryo that becomes a fetus that becomes a baby, one dominant sperm needs to get far enough into the egg to fuse with it—hence the need for strong swimmers! Then, the egg and alpha sperm plant itself in the wall of your uterus and begin to grow.
2. There are only three to five days a month when you can actually get pregnant. Despite all the unintended pregnancies you see in shows and movies, you can't get knocked up any old time you have unprotected sex. Your egg and your partner's sperm are best able to connect when you're ovulating. And if your partner's sperm is seriously persistent, it may survive in the vagina for 24 to 48 hours, giving you about a 48-hour window before and after ovulation for baby-making to happen. The bottom line: All the sperm in the world won't produce a baby if they enter your body at the wrong time (i.e., when the ovary isn't releasing an egg), according to Dr. Sophocles.
3. You should really go sober when you're trying. New recommendations say no amount of alcohol is safe to drink while you're pregnant, but it can take weeks to confirm you're pregnant—and god knows you can throw back a whole case of wine in that window. Because the most important time to lay off booze is during the earliest stages of pregnancy when the baby's heart and spinal cord begin to develop, you're better off stone-cold sober than sorry while actively baby-making.
4. You need to take prenatal vitamins before you get pregnant. Prenatal vitamins contain at least at least 400 micrograms of folic acid, a nutrient humans only need during the first four weeks of life to prevent major birth defects while the spinal cord is developing, Dr. Sophocles says. Because most home pregnancy tests won't detect a pregnancy until a baby is five or six weeks in the making, it's super important for any woman who might possibly get pregnant to take a daily dose of folic acid. While there's no rule that you need to dope up months before conceiving, start as early as you need to ensure you get vital nutrients on the day you conceive—and every day throughout your pregnancy thereafter. (Starting prenatal vitamins too early can't hurt, since you'll just pee out any nutrients you don't need.)
5. You can get pregnant as soon as 24 hours after going off birth control. Unlike oral contraceptives of yesteryear, which contained high doses of hormones and caused lots of annoying side effects, most pills prescribed today have such a low dose of hormones that missing one or two pills can leave you completely unprotected. (It's why so many women get pregnant by eff-ing up their packs.)
That said, hormonal birth control prevents ovulation. If you take it for years and years and suddenly stop popping pills, your body might forget to release an egg during your next cycle, which will prohibit you from getting pregnant right away, Dr. Sophocles says. Chances are, you'll ovulate within a month or two of going off the pill, so if you're trying to plan your pregnancy around a specific season, go off the pill at least a month before you officially begin trying to give your body a head start.
6. There's no evidence that certain sex positions improve your chances of getting pregnant. But certain kinds of sex—like anal, oral, or non-penetrative sex, will certainly reduce your chances: Only vaginal penetration can get you pregnant, for the record.
7. There's no scientific evidence that you need to orgasm to get pregnant. But anecdotally? Dr. Sophocles thinks it could help: Some experts believe that the uterine contractions associated with female orgasms can help mobilize sperm by drawing it up into the uterus toward the egg, so long as your orgasm occurs within 45 minutes of your partner's. (That said, plenty of women get pregnant without having an orgasm—so seriously, no pressure if it doesn't happen.)
8. You're more likely to get pregnant when you have thin, clear discharge as opposed to thicker mucus. Typically, your cervix makes a thick, mucus-y plug to prevent sperm from reaching your eggs. When you ovulate mid-cycle, this mucus thins out significantly—so much that clear discharge is a reliable sign that you're ovulating, Dr. Sophocles explains.
9. It takes a typical healthy couple about six months of trying to get pregnant. Why so long? Dr. Sophocles says timing sex to coincide with ovulation can be tricky—particularly among women with irregular periods who might not be able to nail down the precise dates.
10. Sweaty balls can lower your partner's sperm count. Regular hot tub or sauna use, or any other super sweaty situation, can overheat your partner's testicles, which lowers his sperm count, according to Dr. Sophocles. Luckily, the dip is only temporary and completely reversible—he makes new sperm all the time.
11. Getting high can lower your partner's sperm count. Guys who smoke pot all the time can have completely normal semen. But if you're having trouble getting pregnant, and your partner smokes marijuana on the regular, cutting back can improve your chances of conceiving, suggests Dr. Sophocles.
12. A symptom-less STD can prevent you from getting pregnant. Chlamydia closes off your fallopian tubes—and the only symptom could be trouble getting pregnant. Luckily, as few as four antibiotic pills can clear things up—if you catch it early. Otherwise, your doctor can open your tubes surgically or with a vaginal injection.
13. Stress can prevent you from getting pregnant. Experts don't know why or how. But Dr. Sophocles says she's seen tons of couples stress over conceiving, then take a break from trying, take a relaxing vacation, or remove the pressure by deciding to adopt—and then get pregnant.
14. You're probably horniest when you're most fertile. Sex drive follows fertility, Dr. Sophocles says. "It's a millennia-old phenomenon that makes us propagate as a species."
15. Excess weight can mess with your fertility. A particularly high body mass index can mess with your body's levels of insulin, a hormone that regulates blood sugar but also mediates fertility. Like most health conditions aggravated by excess weight, weight loss can help.
16. Being underweight can prevent you from getting pregnant. If you have a particularly low BMI, you could have low estrogen levels, which can prohibit ovulation—and if you don't ovulate, you can't conceive. Even if you do ovulate, low estrogen might inhibit tissue growth in the uterus, which can make it difficult to support an embryo, Dr. Sophocles says.
17. Excess body hair growth could predict difficulty getting pregnant. In some cases, this could be a symptom of polycystic ovarian syndrome, a hormonal disorder that messes up your period, which makes getting pregnant extra difficult.
18. You might shed more hair than usual when you first get pregnant. Any time estrogen levels shift abruptly or drastically (like when you get pregnant, deliver a baby, or at the onset of menopause), your hair follicles are affected and hair loss can occur, according to Dr. Sophocles. (NBD—it will grow back!)
19. You can get pregnant while you're breastfeeding. When you breastfeed, your body spews out loads of prolactin, a milk-inducing hormone that temporarily shuts off your period. But while you're saving cash on tampons (and busy feeding another human), your ovaries can still release an egg on the DL. Which means having unprotected sex while you're breastfeeding is like playing Russian roulette, Dr. Sophocles says. (And the stakes are high: Another child.)
20. You can get pregnant well into your 40s. Most fertility specialists advise thirtysomethings who want kids to get on it ASAP. But Dr. Sophocles says she sees tons of women in their 40s come to her with surprise pregnancies because they think their age or increasingly irregular periods are as good as birth control. (Lies!) The truth is that you can get pregnant well in your 40s—and without any special fertility treatments. Technically, you're fertile (i.e., susceptible to pregnancy) until your period goes MIA for at least a full calendar year. So chances are, you've got plenty of time!
This article originally appeared on Cosmopolitan.com. Minor edits have been made by the Cosmo.ph editors.