It's what pushes some girls to ignore the signs of pregnancy — until they can't deny it any more, says Carol Cowley, an obstetric-gynecologist nurse practitioner at New Horizons, a teen clinic in Brighton, Colo.

"There's usually some kind of fear or shame about telling the important people in their life they're pregnant," explains Cowley. "They may have a parent who said, 'I'll kill you if you get pregnant.' For many of these girls, that fear is real."

Shariem Izquierdo, a teen parent featured in Surpise Birth Brings Pain and Trouble, said she got her period every month during her pregnancy and didn't realize she was carrying a child until she went into labor.

Cowley says it's abnormal to bleed when you're pregnant, although some women will have irregular, spot bleeding.

A pregnant girl will say "I bled a little," Cowley says, and they grasp onto that as proof they aren't pregnant.

"When there's something we're really terrified of, we look for things that can kind of confirm it's not happening," she explains.

If you know someone who you suspect is pregnant, or if you think you might be pregnant, ask "What's the worst that can happen?"

Being pregnant is a problem, but there are solutions. And the longer you wait to face the problem, the fewer options you have. Plus, if you're going to have a baby, you need prenatal care to make sure it's healthy.

Even though a lot of teens think their parents would kick them out if they came home pregnant, most of the time that doesn't happen. Take Shariem. She thought her mother would kill her, but now her mother is Shariem's biggest source of support.

"It's the rare instance where they're kicked out," adds Cowley. "People usually rally around.

Editors' Note: To learn more about signs of pregnancy click here. Stay on Sexetc.org to learn more about pregnancy options such as abortion, adoption and teen parenting.