To get the facts, BuzzFeed spoke with Mary Jane Minkin, MD — a clinical professor of obstetrics, gynecology, and reproductive sciences at Yale School of Medicine. 1. Your first sonogram will be internal — "I tell my patients it sort of looks like a big magic wand." eduardlaboulaye3 / Via instagram.com Contrary to popular belief, your very first ultrasound will not be performed on the outside of your belly. Dr. Minkin said, "Initially, when the uterus is fairly small, we like to do what’s called a transvaginal ultrasound. It gives us a closer look at where the baby is and we don’t have to go through all the layers of the abdomen to get to the uterus."After about two months, doctors will perform the abdominal ultrasound you're used to seeing and/or hearing about. 2. And, sorry, but you don't get an ultrasound at every appointment. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Bravo Many people think they will get an ultrasound of their baby at every doctor’s appointment, but that isn’t true. Throughout the course of a nine-month pregnancy – if everything looks normal – you will only have about two to three ultrasounds in total.“A lot of times a sonogram will be performed at the first obstetrical visit just to make sure everything is okay. Generally, some doctors will do an ultrasound at about 12 weeks to look for malformations. Doctors will also do an ultrasound at about 16 to 18 weeks, and at that point we’re just looking for overall malformations. But, that’s when we stop doing ultrasounds unless there’s a concern or question...or multiple babies.” 3. The act of sex won't induce labor, but seminal fluid might. TV Land Dr. Minkin said, "Seminal fluid, or semen, is rich in a chemical called prostaglandin which is initially located in the prostate gland and made in many organs of the body. One of its properties allows it to contract uterine smooth muscle. (And we think that menstrual cramps are caused by prostaglandin which is contracting the uterus.) We often use prostaglandin to induce labor. That’s where this belief comes from that if you have sex and seminal fluid is released, the prostaglandin may help stimulate uterine contraction to aid getting the baby out of there. Does it help? We don’t know; it’s hard to say. But we usually tell someone who is having premature contractions not to have sex. There’s all sorts of people that will tell you it helps and there’s some science behind it." 4. Speaking of sex, the baby's head does not get "poked" while you're doing it. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Netflix "No, the baby will not be poked. The cervix is basically closed until the very end of the pregnancy, and even when it starts opening, it’s not a problem. The baby is floating in fluid. There’s amniotic fluid all around the baby. It’s like something in a balloon that is filled with water. If anything comes toward the uterus, it will just bounce out of the way. The baby will not be poked, not to worry." 5. A male fetus will get erections in the womb. NBC "Yes, they get erections, but they do not make sperm." 6. And a female fetus's eggs are formed in utero. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF City TV "A baby girl’s eggs are basically formed in utero. Girls actually have the highest number of eggs in utero. And by the time they are born, they’ll have lost some of their eggs." 7. A baby is actually 38 weeks (not 40 weeks) during a full-term pregnancy. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF HBO "When I say six to seven weeks gestation, that’s weeks from your last period, which from conception is really four to five weeks. Usually you conceive about two weeks into your menstrual cycle. So, that’s a common misunderstanding as far as what are weeks pregnant. When I say 40 weeks is term, that’s 38 weeks from conception." 8. Pregnant women don't need to "eat for two," they only need about 300 more calories a day during pregnancy. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Paramount "The preferred thing to do during pregnancy, because of some of these digestive issues, is to eat frequent, small meals. You’re going to be much more comfortable." 9. In utero, a baby's lungs are filled with amniotic fluid (which is actually their own pee) and they breathe it in and out. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Buena Vista Doctors suction the fluid out of the baby's lungs right after they're born. 10. Babies pee, but they do NOT poop in the womb. youtube.com "Babies, in general, don’t poop (in the womb) unless they’re distressed. They are swallowing, but they don’t poop, per se." 11. Some pregnant women are horny all the time...and some are not. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF NBC "Some women’s sex drive does go up, but it doesn’t happen for everybody by a long shot. Do we know exactly why? Probably not. I think for some, it’s just psychological. It’s very hard to say what would make people have that desire." 12. "Pregnancy brain" is probably just fatigue. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF youtube.com "I think there’s something real to 'pregnancy brain.' Why you have it, we don’t know. I think part of it is fatigue and I think part of it is the fact that you're not comfortable, so you aren't getting quality rest." 13. Babies can hear inside the womb. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF DreamWorks "We definitely know babies hear. Do they know if it’s their mom’s voice? I don’t know; that’s debatable. There’s no research showing that." 14. Pregnant women pee a lot because of hormonal changes and pressure on the uterus. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF youtube.com "Some of the hormonal changes in pregnancy give people the feeling that they need to pee. Progesterone levels go up. Early on, it’s not necessarily pressure from the uterus, it’s more of a hormonal change than the sides of the uterus pressing on the bladder. But throughout most of the pregnancy, the uterus is pressing on the bladder. The bladder is actually attached to the uterus. When you do a C-Section, you actually take the bladder off of the uterus and put it back." 15. Having frequent heartburn during pregnancy does not mean your baby will have a lot of hair. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF 20th Century Fox "It’s a very common myth that if you have heartburn your baby will be hairy. There’s no science to it, but a lot of people believe it. However, heartburn is very common and there’s a very easy explanation why. The valve between the stomach and the esophagus – what’s called the cardiac sphincter – relaxes because of the high levels of progesterone, then the stomach is full of acid. Because all the acid in the stomach and the pressure from the uterus is pressing things up, the valve that used to be closed, is open, so all of that acid can just reflux.” 16. Exercise is very safe during pregnancy. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Touchstone "The major concern you have with exercise in general is body heat. Because if you get your core temperature up significantly and keep it there for awhile, there are some malformations that can be associated with prolonged elevated temperatures, especially early in the pregnancy. But you’d have to be running pretty hard and keep your temperature up for a couple of hours. Running is fine as long as your comfortable and not contracting." 17. You could be pregnant for over a year. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF CW "Theres are cases — and this is very rare — where a thing called superfetation happens. This is where people can get pregnant while still being pregnant, usually early on. It’s a rare entity, but it does happen occasionally. There are people who are pregnant and have another pregnancy on top of it."