"I was so scared, and I was sure I was pregnant," she recalls. "I was on the verge of calling my doctor when my period came. Then I realized how unsafe I'd really been."

Laura was unsafe and lucky. A sexually active teen who doesn't use contraceptives has a 90 percent chance of getting pregnant within the year. And every year, three million sexually active teens (around one in four) get an STD, according to the Alan Guttmacher Institute (AGI), a reproductive health research organization.

Common Behavior

Laura is just one of many sexually active teens in the United States who have intercourse without protection.

Two-thirds of all 9th through 12th graders have had sexual intercourse by the end of 12th grade. Surprisingly, only 58 percent of them used a condom the last time they had intercourse. And only 18 percent reported that they or their partners used birth control pills, according to the 2001 Youth Risk Behavior Survey by the U.S. Centers for Disease Control and Prevention, in Atlanta, GA.

Why are sexually experienced teens being so unsafe?

"There are two major reasons why they don't use contraception: lack of access and lack of information," explains Mary Jean Schumann, executive director of the National Organization on Adolescent Pregnancy, Parenting, and Prevention, in Washington, D.C.

"The biggest reason is a true lack of knowledge. Many teens get incredible amounts of misinformation from friends and the media. They're very misinformed about safer sex and what puts them at risk for pregnancy and STDs, including HIV. They tend to discount a lot of risky behaviors."

Risky Teens

Many sexually active teens still believe, for example, that just using birth control (the Pill) during intercourse or giving oral sex to someone without using a barrier method is "safe sex."

Joe Turner, 19, from Lafayette, LA, started having sex with other males when he was 17. But he only recently found out about the importance of using condoms.

"I didn't really know about using condoms for anal sex because I knew that I couldn't get another man pregnant. I never really thought about diseases," he says.

After his friend was diagnosed with an incurable STD, Joe's outlook changed.

"I don't have anal sex anymore, because I don't feel like I can trust anyone enough about his sexual history," he says.

But he continues to be unsafe during other sexual activity.

"I still have oral sex, but I don't ever use condoms. I guess it just feels better without them," he explains.

Like Joe, sexually active teens give different reasons (or excuses) for having unsafe sex. Some are misinformed about STDs and unplanned pregnancies. Others know about and have access to contraception, but still don't use any during sexual activity.

Take Alexander, 18, of Swarthmore, PA.

"My girlfriend doesn't want me to wear a condom," he says, "and having sex without it is better than nothing. We're both smart people. I know something could happen, but I wouldn't do it unless I really trusted her."

Other teens have "more complex" motivations, explains Schumann, "which have to do with their hopes for the future (beyond having a baby), self-image, and feelings of value and worth."

And some teens lack the communication skills necessary to insist that their partners use protection.

"Once, I asked my boyfriend to put a condom on," remembers Fahtema, 18, from Cleveland, OH. "He said 'no,' and told me never to question any of his decisions. He told me not to worry about getting pregnant. I really liked him a lot. He was older, and I trusted him."

Fahtema's experience is similar to other teens who have older sexual partners. According to a recent study by AGI, if a teen couple has an age difference of two years or more, the couple is less likely to use contraceptives.

Scared to Get Care

More than nine out of 11 teens recently surveyed by the Henry J. Kaiser Family Foundation and Seventeen magazine were "afraid" their parents would find out if they received services, including contraception, from a family planning clinic. Teens like Sean, 17, from Philadelphia, PA, are afraid of reaction from peers, too.

"I wouldn't want to walk into the 7-11 in my town and buy condoms," he explains. "It would be too easy for someone from school to see me. Kids I know work there. Too many people would find out."

Having a few people know that you have sex, however, is better than introducing them to your baby later on or explaining to them that you have an incurable STD. Not having sex or using two forms of contraception like the Pill and a condom—every time you have sex—is the only way to make sure that you'll be safe and healthy.

Editors' Note: For low-cost reproductive health services, visit your local family planning clinic. You can fin one by clicking here, or checking the yellow pages under "family planning" or "clinics." Or schedule an appointment at a Planned Parenthood near you, call 1-800-230-PLAN (7526).