Along with other Sex, Etc. editors, I asked some teens to reveal the most common myths they’ve heard about sex. We heard plenty – on everything from masturbation to first sexual intercourse. I took six of the most common sex myths and set out to get some accurate information from Dr. Barbara Snyder, chief of Adolescent Medicine at the University of Medicine and Dentistry of New Jersey. She helped me reveal the truth behind these common and popular sex myths.

Myth: You’re not at risk for getting a sexually transmitted disease (STD) if you receive oral sex.

Fact: Many STDs can be transmitted through oral sex, even when you receive it. Herpes and gonorrhea are two that can be easily transmitted this way. Herpes are sores that can appear around the mouth or on the genitalia. If a boy has herpes on his mouth and he performs oral sex (cunnilingus) on a girl without using a dental dam -- it's very possible for him to pass the virus to the girl's vagina. (A dental dam is a square piece of latex that is put over the vagina.) The same can happen if a girl has herpes on her mouth and she performs oral sex (fellatio) on a boy without using a latex condom. She can pass herpes to his penis.

Gonorrhea, a bacterial STD, is often passed during vaginal or anal intercourse. But if a person’s mouth comes in contact with an affected area, she or he can contract oral gonorrhea and have a bad sore throat. 

The best way to stay STD-free is to refrain from any sexual activity. But if you’re going to be sexually active and have oral sex, always use protection. A guy should always wear a latex condom when he's receiving oral sex, and a girl should always wear a dental dam.

Myth: A woman can’t get pregnant if she has sex during her period.

Fact: This is not true. Risk of pregnancy is based on when a woman ovulates. It’s not always possible to predict when a woman will ovulate. Sperm can stay alive and active in the female reproductive tract for up to seven days (the average is three days). And the ovum (egg) survives for 24 hours after ovulation. So it’s possible for a woman to get pregnant from seven days before ovulation to three days after it. 

Menstruation should not be used as a form of birth control because the female reproductive system isn’t always predictable -- especially in teenage girls. If you’re going to have intercourse, make sure you use two forms of protection. Use a hormonal method (the Pill) to protect against unwanted pregnancy and a barrier method (latex condom) to protect against STDs.

Myth: Being turned on by same-sex fantasies means you’re gay.

Fact: During our teen years, we often explore different parts of ourselves. This means discovering attractions for certain people. For instance, you might discover that you’re attracted to girls or boys – or both. Some teens dream about relationships with someone of the same sex, and then wonder if it means they’re homosexual. This isn’t always the case. Sometimes you dream about being intimate with a person of the same sex because you feel really emotionally close to him or her. Maybe he or she is a mentor or a good friend. 

Of course, sometimes these fantasies can reveal something about your sexual orientation. If you’re fantasizing about a member of the same sex and want to pursue the relationship in real life, then it’s possible that you might be gay or lesbian. It's important to explore your own feelings and decide what you want -- and not base decisions on fantasies. Eventually, sexual orientation becomes clear to us.

Myth: All women bleed the first time they have intercourse.

Fact: A woman will most likely bleed when she loses her virginity because her hymen is broken by penetration. (The hymen is a thin piece of skin surrounding the vaginal opening.) A woman was once thought to be a virgin until her hymen was broken (or "enlarged"). But the hymen can be broken through ways other than sex. First of all, just going through normal growth can stretch a girl’s hymen out. The hymen can also be broken if a girl uses tampons, or is fingered. Bleeding during first intercourse usually means that there’s still a large part of the hymen covering the vaginal opening, which has been broken (or enlarged) by penetration of the penis. Bleeding can also be caused by lack of lubrication in the vagina.

Myth: Even if we say masturbation is OK, it really isn’t.

Fact: Masturbation is a controversial issue in our society. While some think it’s perfectly normal, others strongly disagree. If a person’s religion or culture teaches them that masturbation is “wrong,” then doing it may make them feel guilty or bad. But actually, masturbation can be healthy. It allows people to release sexual tension without worrying about STDs or unwanted pregnancy. It also helps people find the sensitive areas they like to have stimulated. If they choose to have intercourse, this helps them communicate to their partners about where they like to be touched.

Myth: Women always have orgasms just from intercourse.

Fact: Different women orgasm from different types of stimulation. Some women can orgasm just from vaginal intercourse, but many others can’t. Why? The most sensitive part of a woman’s body is the clitoris, a small “bump” filled with nerve endings that exists just to give a woman pleasure. Many women only orgasm when the clitoris is stimulated. The clitoris isn’t usually stimulated during vaginal intercourse since it’s located between the lips of the labia (soft folds of skin inside the vulva). There usually has to be some other type of stimulation during intercourse to help a woman orgasm. So, a better way to help a woman orgasm is by stimulating the clitoris with fingers or the tongue.