Ohio based cheerleading coach, Ally Opfer, went to the hospital late one night for severe abdominal cramping. Doctors, nurses and techs drew vials of blood, started an IV and did a pregnancy test—which was negative.

She lay on the exam table getting an ultrasound, waiting for the worst. Here's what happened instead, (as told by Ally to Love What Matters):

"Then, all of a sudden, not only did my doctor come flying in the room, but so did literally 10 other people who I had yet to see that night. As all these doctors and nurses filled my room, I was preparing myself for the worst news possible, that I was dying. There were so many doctors and nurses in my room all with a sense of urgency that I knew whatever was happening to me was very serious.

"Then, the doctor said these words to me: ‘Have you ever been pregnant before?’ I, of course, said ‘no,’ very confused. He said, ‘Well, it looks like you’re about 38-weeks pregnant and 10-centimeters dilated. You are in full blown labor, and we need to get you upstairs to labor and delivery now!’"

Ally was rushed into the operating room for a cesarean section—her blood pressure was high, and the team decided that a cesarean birth was the safest option.

She writes, "As I waited for them to tell me the baby was out, it felt like forever. Then I heard, ‘Time of birth: 3:31 a.m.’ and my mom and I looked at each other and were just saying, ‘Cry. Please cry. Please start crying little baby,’ so we knew the baby was okay and healthy. He finally started crying, and so did we. That’s when it finally hit me that I was actually in labor and I had just given birth. I laid there crying (happy tears) and was in shock listening to my baby’s cry. I couldn’t see him, but I could hear him."

Ally said, "My whole family was filled with joy to have this unexpected, magical gift. He’s my parents’ first grandbaby. He’s the most amazing Christmas gift I could ever receive."

I meeeaaannnn with that cute little face, we totally get it.

Stories like Ally's are always followed by people asking if it's really possible to be pregnant without knowing it. It's actually quite possible.

In fact, it's estimated that it happens to about one in 450 women. It may not be common, but it's something we should definitely be aware of.

Everyone's story looks different, and there are probably many more factors than these, but here are seven things to consider:

1. Many women have irregular periods

The tell-tale sign of being pregnant is often missing your period. But what if you're used to "missing" your period?

About 30% of women experience irregular periods. Irregular menstrual cycles can happen for a variety of reasons, including polycystic ovarian syndrome, use of hormonal birth control, thyroid issues, over-exercising, stress, breastfeeding and more.

If a woman has irregular periods, she may not suspect pregnancy for some time.

2. Not tracking cycles

Have you ever had the thought, "Ummmm... when was the last time I got my period?" If so, you are definitely not alone.

In a recent study, researchers found that as many as 68% of women were not tracking their menstrual cycles, and 53% didn't know when their next period would be. Between juggling the demands to work schedules, kids and simply life, it's quite easy to lose track of your menstrual cycle, and not realize that you're "late."

3. The menstrual cycle is confusing

Most women have at least some degree of uncertainty about their menstrual cycles. Researchers found that less than one-third of women surveyed knew about reproductive hormones. About 47% of women did not know what ovulation was (when the egg is released) and almost 50% didn't know how long the average menstrual cycle should be.

The laws around sexual education in school vary tremendously by states—only 24 states and the District of Columbia mandate it. So, while some people may have a lot of exposure to the information, many do not.

4. Birth control

With the exception of abstinence, there is no such thing as an error-proof birth control method. Here are some methods of birth control, and the percentage of women using them that become pregnant each year "with typical use:"

  • Spermicide 28%
  • Fertility awareness-based methods 24%
  • Male condom 18%
  • Diaphragm 12%
  • Pills (combined and mini) 9%
  • Depo-Provera 6%
  • IUDs 0.2-0.8%
  • Vasectomy 0.15%

If using birth control, a woman may not be on the lookout for pregnancy symptoms—so it would be easy to miss them, and not know that she's pregnant.

5. But what about the bump?

Women carry pregnancies differently. While some women start showing very early in their pregnancies, others barely show when they are full-term. If, for example, a woman has an anteverted or tilted uterus, she may not "look" pregnant for a while. Tall women tend to show later than shorter women. Every body is just different.

6. And the symptoms?

That varies too. When we think early pregnancy, we think "oh-the-nausea." But it turns out that 20% of (lucky) women never experience pregnancy-related nausea.

And, the symptoms of pregnancy are pretty vague—nausea, tiredness, bloating and headaches could all be caused by so many things, it would be easy to assume that something besides pregnancy was the culprit.

7. What about fetal movement?

Women experience sensations differently. While some women may feel like they have an actual village living in their bellies, others may not be as aware of the movement. And the feelings can be hard to pinpoint. Many times people think fetal movement is just gas or belly rumbles, for example.

Women who have anterior placentas (toward the front of their bellies) often feel less fetal movement than women with posterior placentas (toward the back).

Even women who do know they are pregnant miss the movements. A study found that 83% of women were asked to do fetal kick counts by their providers—that means that 17% were not. The same study reported that only 16% of women actually did fetal kick counts and that many women were confused by how to do them.

(Psst: We love this app for doing fetal kick counts, btw!)

Lastly, many women experience a phenomenon called phantom fetal movement, where they think they feel a baby kicking even though they are not pregnant. If a woman has experienced that, she may not think much of actual fetal movements when they happen.

To sum it up, every pregnancy and woman is different. We all need each others' support as our motherhood stories unfold.

We wish Ally and adorable little Oliver all the best!