Whether you're a first-time mom[1] or pregnant with your third baby, your doctor probably has talked to you about what to eat and what to avoid, why exercise is important and what tests you'll need.

But let's face it, doctor's visits are short[2], so there might be some things she's overlooked.

Here are 10 things you should know to make sure you'll have a healthy pregnancy and be prepared once your labor starts.

1. Your doctor works for you.
 When you choose a doctor, you're selecting that person to provide information and services much like you would hire a home contractor or a personal trainer. Of course the information is evidence-based, the services are premium and the cost is high, but it's important to remember that ultimately you're in charge of your pregnancy, labor and delivery and you have choices.

"It's your job during pregnancy to become informed and your physician is there to be your guide," said Jeanne Faulkner, a registered nurse in Portland, Ore., author of "Common Sense Pregnancy: Navigating a Healthy Pregnancy and Birth for Mother and Baby" and host of the Common Sense Pregnancy & Parenting podcast.

2. Don't rely on a missed period.
 Instead of rushing to make an appointment the minute you realize you missed your period, take a drug-store pregnancy test first.  Then see your doctor to confirm the results and find out how far along you are.  If your periods are usually irregular, you could actually be further along in your pregnancy than you think.

3. Pregnancy is normal.
 "[Pregnancy] is probably the first time in your life that you're going to your doctor for something that's completely routine and normal," said Dr. Brian Levine, a board-certified OB-GYN and fertility specialist, and the New York practice director for the Colorado Center for Reproductive Medicine in New York City.

Although pregnancy in the U.S. is often viewed as a medical event or a condition that is difficult to manage and needs intervention, remember that your body is uniquely suited for it.

4. If you drank when you conceived, don't stress.
 Had one too many drinks the night you conceived? You're not alone. Fifty percent of pregnancies in the U.S. are unintended and chances are, many are a result of alcohol.

Although alcohol can impact fertility and you should never drink during pregnancy[3], if you were drinking when you conceived, it will have no effect on your baby, Levine said.

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5. You might want a midwife instead of an OB-GYN.
 More than 90 percent of women will choose an OB-GYN as their providers, but for some women who are healthy and not considered high-risk, a midwife might be a better option.

"Midwifery care is slanted to look at pregnancy as a normal, healthy physiological process for the majority of women," Faulkner said. 

Obstetricians on the other hand, are actually surgical specialists for high-risk patients and they use screening, diagnostic exams and interventions to rule out issues. 

"They have been trained to be medical specialists [and] to look for problems and that's how they look at pregnancy," Faulkner said.

6. You only need two ultrasounds.
 It's exciting to see your baby and it can also put your mind at ease, but the reality is that you only need two ultrasounds throughout your entire pregnancy. The first one, a nuchal translucency (NT) scan, is usually done between 11 and 12 weeks, along with a blood test. The NT scan screens for birth defects like Down syndrome and it can also give you a good idea of your due date. The second ultrasound, which happens between 18 and 21 weeks, is a screen of the baby's anatomy.

7. Ultrasounds aren't always reliable.
 Since ultrasound can be off by as much as 20 percent in either direction, physicians will also use a tape measure and their hands to estimate the baby's weight. Ultrasound is also more accurate in the first trimester than in the third.

"You can get a very clear idea of how big a baby is in the first trimester, but that doesn't necessarily correlate to how big [the baby] will be at delivery," Faulkner said.  

What's more, the only way to measure amniotic fluid levels is with ultrasound, yet if the umbilical cord or the baby's hand is in the picture, it can skew the accuracy.  If your physician is concerned, there are other tools she can use like a non-stress test to determine next steps, Levine said.

8. Just because you want to know the gender, doesn't mean you should.
 Prenatal cell-free DNA screening, also known as non-invasive prenatal testing, is designed to look for chromosomal anomalies. Although you can also find out your baby's gender early, it's not a medical indication for the test and shouldn't be done just because you're curious, Levine said.

If you decide to have the test, understand that since it's new technology, you should be prepared that if the results are abnormal they could turn out to be normal later on.

9. Your birth plan isn't a contract.
 Having a birth plan is a great idea because it shows the nursing staff that you're prepared, you have an arsenal of tools to help you manage labor and you want to set the tone for the type of birth you want to have.

Yet there are so many unknowns. For example, you don't know what your pain threshold is, how your labor will progress and how your baby will tolerate labor. Instead of making hard and fast rules and expect everything to go as planned, "go in a set with of really good ideas and then be flexible," Faulkner said.

10. Just because it's past your due date doesn't mean you're overdue.
Some women and physicians may opt for an induction if a woman goes past 40 weeks, but a due date is really just a guess date. In fact, only about 5 percent of mothers actually go into labor on their due dates.

Women who are 42 weeks pregnant are considered overdue, but approximately 90 out of 100 will have contractions start on their own within 2 weeks.

The concern of going past 40 weeks is that the placenta will not work as well. Yet this is rare and your physician has tools to monitor your baby's health.

"We can put a woman on a fetal heart monitor or do an ultrasound and a biophysical profile to determine fetal well-being," Faulkner.

Julie Revelant is a health journalist and a consultant who provides content marketing and copywriting services for the healthcare industry. She's also a mom of two. Learn more about Julie at revelantwriting.com.