There are more old wives' tales about conception and pregnancy than probably any other event in health and medicine. Here are some of the conception myths I hear most often, as well as the facts that debunk them.

Myth # 1: You can't exercise while trying to conceive.
In general, exercise is healthy and will not affect your ability to conceive.

Myth # 2: You can control your baby's sex.
Evidenced-based medical trials have not been able to prove that timing intercourse relative to ovulation can increase the chances of conceiving a girl or a boy. In fact, couples that try to follow these methods may have more trouble reproducing because they may avoid having intercourse at the most optimal times for conceiving.

Myth # 3: You better reproduce in your 20s, or you're out of luck.
There is no exact threshold after which conceiving is less likely. We do start to see a steeper decline in fertility in women in their late 30s and 40s. Conception rates also seem to decline as the man in the relationship gets further beyond age 40.

Myth # 4: If you don't get pregnant right away, then you are infertile.
In general, there is about a 15% chance each month that -- when trying under normal circumstances -- a couple will successfully conceive…Think about that for a second. If you have everything going perfectly for you, and you have no barriers to conception, you have only a 15% chance EACH MONTH of conceiving. Before I got into medicine I -- like most of you, I'd bet -- assumed this percentage was much higher.

Myth # 5: Once you get pregnant, miscarriage is very rare.
I think this misconception arises because many couples will not share with friends and loved ones when they have experienced miscarriage. They will, however, advertise if they are pregnant and doing well. In reality, miscarriage rates usually fall between 15% and 20%.

Myth # 6: You must avoid all alcohol while trying to conceive.
Obviously, high levels of alcohol should be avoided (greater than 2 drinks a day). However, several studies show that moderate alcohol consumption has no effect on fertility. With that said, once you find out you are pregnant alcohol should be avoided.

Myth # 7: Frequent ejaculation decreases male fertility.
Medical studies show maintenance of normal sperm quality and quantity, even with daily ejaculation. Abstinence of greater than 5 to10 days can lead to a decrease in healthy sperm cells. In general, couples should have sex daily, or at least every other day, during their fertility window.

Myth # 8: If you want to get pregnant in a year, you should stop your birth control now.
In general, there is little delay in conception from cessation of most birth control methods. The exception seems to be the "shot", which may lead to a few months delay in conception for some women -- not all.

Myth # 9: Different positions during and after sex can increase your chances of conceiving.
Post-sex rituals, such as lying on your back with your legs in the air, have no effect on the likelihood of conception. Nor does one sexual position result in higher conception rates than others.

Myth # 10: You're more likely to get pregnant if you have an orgasm during sex.
The presence or absence of female orgasm does not affect your likelihood of conceiving.