15 Reasons Women Don't Know They're Pregnant Until Giving Birth

Most women think if they were pregnant there's no way they wouldn't know. There's the throwing up, the missed periods, and it would be pretty hard not to notice you've gained a bunch of weight right in your stomach area. But many doctors emphasize that not every woman is guaranteed to experience every possible symptom of pregnancy, and even if they do, they aren't necessarily going to experience it in the way they expect or how the people they know have experienced it.

TLC's show I Didn't Know I Was Pregnant tells the stories of women who went through months of being pregnant, not changing a single one of their habits (good and bad), without it ever crossing their mind that they might be pregnant. Imagine having a stomach ache that turned out to be a full grown newborn baby? Pretty terrifying.

Here are 15 reasons some women don't know they're pregnant until they're about to give birth.

15 Periods continue

We all know one of the first signs of pregnancy is a missed period. So it's not really a stretch for a woman to assume she's not pregnant if she gets her period. But most likely, what she thinks is a period is really just spotting, which many women experience during pregnancy. Also, women who have a history of irregular periods might not think it's unusual to have a really light period, or go for a few months without having one at all. If she's not paying close attention to other symptoms, unusual periods wouldn't seem like anything to worry about.

14 Fertility issues

Fertility issues affect millions of men and women who are trying to have a baby. A doctor might tell a couple that they won't be able to get pregnant naturally because of health reasons, so when they actually do, it's so unexpected that it doesn't register that they're pregnant. If the guy has had a vasectomy or the woman has had her tubes tied they might think it's impossible to get pregnant, so they aren't using any birth control. But in rare cases it's possible for a vasectomy to reverse itself.

13 She might think she's going into menopause

Generally, women start going into menopause around the age of 50. This is when their periods start to become fewer and further between and having kids is no longer recommended, or even possible. But a woman in her mid forties might mistake symptoms of pregnancy for early menopause. She might have already decided that she's too old to have kids, so getting pregnant isn't on her radar. But some of the symptoms can be similar, so if she's not paying close attention and talking to a doctor about the changes in her body, she might not realize what's really going on.

12 Birth control

Women take birth control pills, use a patch, have an IUD, or take a birth control shot for a reason-- they want to avoid an unwanted pregnancy. So what happens when those birth control methods fail? When used correctly, it's pretty rare for a woman to still get pregnant while using any of the above options. But there's always human error-- like missing a pill for example. Also, other methods of birth control, like condoms, are very effective when used correctly, but condoms can break. The only 100% effective method of birth control is abstinence, and where's the fun in that?

11 Already overweight

Most woman of average body weight (a BMI between 18.5 and 24.9) can expect to gain anywhere from 25 to 30 pounds during a normal pregnancy. But every woman holds weight differently, and that includes when they're pregnant. For a woman who's already overweight, especially with excess fat around her stomach, it might be difficult to tell if she's pregnant or not. She might be used to weight fluctuations and stomach fat, and a little extra isn't anything new.

10 Barely gained any weight

Since usually a healthy pregnancy means gaining at least a little bit of weight, doctors don't advise women to actively try to lose weight while they're pregnant. But if she started a new diet and exercise plan before realizing she was pregnant, that might affect how her body shows signs of pregnancy. Any weight she's losing might cancel out the weight she's gaining. She might also assume stress and her new eating habits are causing the changes rather than an unexpected pregnancy.

9 No morning sickness

Another one of the big indicators of pregnancy for a lot of women is morning sickness. Despite the name, morning sickness doesn't always happen in the morning. It's just a general feeling of nausea and having to throw up for no obvious reason. A lot of women experience very mild morning sickness, so they think it's just because they ate something that didn't agree with their stomach. Either that or they don't feel sick at all, which if you ask any woman who's ever been pregnant, sounds pretty awesome.

8 Drug use

A woman with a drug problem probably wouldn't be in the right state of mind to realize, and then accept, that she's pregnant. The drugs would mask any pregnancy symptoms she might be having, and they would affect her ability to gain weight. Of course, if she's doing drugs throughout her pregnancy, her baby is probably going to be born with a lot of health problems, like low birth weight, physical defects, and mental disabilities. Some women manage to kick a drug habit for the sake of their unborn baby, but that only works if they're able to see a doctor who can confirm their pregnancy and help them get clean.

7 The pregnancy test came back negative

Most women opt for a home pregnancy test if they suspect they might be pregnant. Those tests measure the level of a hormone called human chorionic gonadotropin (hCG) in the urine. If levels are elevated, it could mean she's pregnant. These tests claim to be 99% accurate, but that's only when they're used correctly. Sometimes if they're taken too early they could result in a "false negative" which means they say you aren't pregnant when you really are. One negative at-home pregnancy test definitely isn't enough to rule out pregnancy 100%.

6 No physical side effects

Other than morning sickness and gaining weight, there are lots of other symptoms that come along with pregnancy. Many women experience fatigue, heartburn, indigestion, aches and pains, tender breasts, and food cravings. And those are just the non-life threatening side effects. Some women develop things like high blood pressure (called preeclampsia), and gestational diabetes which can affect the long term health of both the mother and the baby. But if symptoms are mild, women might assume her fatigue and indigestion are due to a poor diet or lack of sleep.

5 Denial

Many women might be so terrified at the thought of having a baby that they notice pregnancy symptoms like morning sickness, missed periods, and fatigue, but they choose to ignore them. For example, a teenager who's afraid to tell her parents she's pregnant might prefer to hide it and pretend it's not happening. But obviously that doesn't make the pregnancy go away and eventually she'll have to face it. She might be too young to really think about the consequences of giving birth.

4 Distracted by stress

A woman with a busy career might not be expecting to get pregnant and has taken precautions to prevent it from happening. So if it does anyway, she's so busy with work and her life that the thought of a baby doesn't even cross her mind. She might think any weight gain and fatigue are just due to not getting enough rest in general, but she's used to feeling that way. Also, if she's dealing with an emotionally traumatic event, like the death of a loved one, that might prevent her from paying attention to her body as well as she should be.

3 Suffering from a mental illness

When people hear about a woman who didn't know she was pregnant, they often attack her intelligence or assume she has some kind of mental illness. It's very possible that a mental health issue could impact a woman's ability to acknowledge pregnancy symptoms for what they are. If she's depressed she might not have the energy to care, and if she lives with something like schizophrenia or bipolar disorder, she might be confused about the changes in her body. But many women who are perfectly healthy still don't realize they're pregnant.

2 The baby wasn't very active

Most women report experiencing their baby moving around a lot inside them during the third trimester especially. They kick, shift around, and push on the walls of the uterus with their growing limbs. But some babies aren't as active as others, so when they do move, the mother just thinks it's gas or indigestion. The position of the baby can also affect how a woman is showing her pregnancy and how much the baby moves around. If it's in breech position (with the feet towards the bottom of the womb), it probably won't kick very much.

1 A combination of all these reasons

Since there are so many symptoms of pregnancy and every woman experiences a different combination of them at different times and at different degrees, it's impossible to know exactly what pregnancy will be like for you. Women who don't realize they're pregnant until they give birth probably expected pregnancy to be a certain way, and when it's not, they overlook the symptoms they do have and blame them on other things. That's why it's important to pay attention to your own body and follow your instincts. Because although having a baby is stressful no matter what, it's definitely helpful if you have a few months to prepare.