When it comes to sex, most of us think we know it all--or at least enough that we don't need further education. But no matter what your background or relationship status, you've probably heard (and believed) a sexual falsehood somewhere along the line. Maybe it was an old wives' tale about physical attraction or an urban legend about what's normal in the bedroom. Read on as we uncover the top 10 myths about sex.

1. Singles have more sex than married people. Contrary to popular belief, it's married people who have more fun. According to Linda J. Waite and Maggie Gallagher's The Case for Marriage, approximately 40 percent of married people have sex twice a week, compared with only 20 to 25 percent of singles and cohabitating couples.

2. Men think about sex every seven seconds. As it turns out, this is fiction, too. According to a 1994 "Sex in America" survey, 54 percent of men think about sex every day or several times a day, 43 percent think about it a few times a week or month, and 4 percent think about it less than once a month.

3. Women are naturally more monogamous than men. Although it's difficult to prove or disprove, researchers believe this popular assumption is more a matter of perception and socialization than biology. As they point out, in most mammalian species, both the males and females are highly, and equally, promiscuous.

4. Pornography is an addictive substance. Some people view porn as a harmless pastime, while others see it as a health hazard. Either way, most scientists agree that although it's possible to become addicted to pornography, the addiction is behavioral, much like an addiction to gambling. Porn itself is not an addictive substance in the category of heroin or cocaine.

5.Herbal aphrodisiacs can enhance your sex life. Ginger, coriander, or cardamom can enhance a host of recipes, but sadly, they won't succeed in spicing up your sex life. A review by the FDA revealed that no purported aphrodisiac has ever been scientifically proven to increase sex drive. And some, like Spanish Fly, can even be potentially dangerous.

6. Sex during pregnancy will hurt the baby. Believe it or not, sex is perfectly safe during the vast majority of pregnancies. In fact, most couples can keep having sex until the woman's water breaks. However, there are cases in which sex should be avoided, so be sure to talk to your doctor if you have any concerns.

7. Women can't get pregnant during their period. Couples who believe this myth may be in for a big surprise. According to a 2000 study conducted by the National Institute of Environmental Sciences, at least 2 percent of women enter their fertile period only 4 days into their menstrual cycle, and 17 percent enter it by the seventh day. Sperm can live for up to five days, so this myth has likely resulted in many unplanned pregnancies.

8. Sex the night before an athletic event will ruin your performance. Although some coaches and athletes advocate abstinence the night before competitions, scientists are quick to point out that there's no evidence to support this myth. In fact, 2000 study published in the Journal of Sports Medicine and Physical Fitness reported that sex had "no detrimental influence on the maximal workload achieved or on the athletes' mental concentration."

9. Talking to kids about sex will encourage them to have sex. It might be uncomfortable or a little embarrassing, but talking to children about sex doesn't encourage them to have it. According to the American Academy of Child Adolescent Psychiatry, open communication helps kids to make healthy and appropriate decisions regarding their sexual behavior.

10. Men and women can't be friends because the sex part always gets in the way. A study published in the Journal of Social and Personal Relationships found that men and women can indeed have platonic relationships. The researchers, who tracked 20 pairs of friends, confirmed that "friendship attraction"--a connection devoid of lust--between the genders is a bona-fide bond.