Unplanned Pregnancy Changes Teen's Life They're well-to-do and they have a problem -- but they're not alone. The family of Hannah, a high school senior in Yakima, Wash., is facing a quandary that more than 729,000 American families deal with every year: teen pregnancy. Even their very nice house in their very nice, sheltered orchard didn't keep Hannah, 18, safe. Neither did all her high school achievements. "I was a homecoming king and queen with my boyfriend of three years," Hannah told "Primetime" in an interview in her hometown. I was a cheerleader, I played volleyball, I was in a lot of school activities. I really was part of the school. Last fall Hannah found out she was pregnant by her on-again, off-again boyfriend, Taylor. He was a B.M.O.C., a champion athlete. They were an all-star couple. Watch "Primetime: Family Secrets" TONIGHT at 10 p.m. When I hear an auditorium cheer for Taylor ... You know, he deserves it," said Hannah. He's worked really hard pretty much all his life to get where he is. But all of that was derailed by a single moment. Hannah explained how it happened. "I used to be on birth control," she said. I just forgot to take it. Me and Taylor would break up and get back together so much it just messed up my period, so I stopped taking it. We used a condom every time until we were on a break and it was spur-of-the-moment. I did Plan B [emergency contraception] after that, but evidently it didn't work. According to Mark Regnerus, an assistant professor of sociology at the University of Texas at Austin and author of "Sex & Religion in the Lives of American Teenagers," upper-middle class teens are more likely to use Plan B as a source of protection. "It's not surprising that Plan B would be more popular among the upper-middle class," Regnerus said in a telephone interview. They're a more strategic group of kids that have a strong orientation toward their future. I'd be willing to bet, however, that their use of it is not to replace contraception but to augment it, 'just to be safe.' That is, few such kids are consciously playing sexual Russian rouletteâ¦ Plan B is for when they've 'messed up.' CLICK HERE to see photos of Hannah throughout her pregnancy. Teen Pregnancy: The Day She Found Out Hannah's best friend, Karly, remembers the day she found out. "I was with her when she found out," Karly said. We were actually at a basketball game watching Taylor, and she was like 'Well, I haven't had my period,' so we went and bought a pregnancy test. And we came back, and we did it and she found out she was pregnant. She immediately started crying and she's like, 'What do I do?' And she told him, and then it was just kind of crazy after that. "When Taylor found out, he was surprised and he didn't take it well at all," said Hannah. It was my first ultrasound and I was like seven-and-a-half weeks or something. The lady was like, 'Oh my God, you're never going to believe this.' My sister ... was like 'Oh my God, twins' and the lady was like, 'No, triplets!' I felt like I was in a dream because it did not feel real at all. Hannah found herself multiplying the expense of diapers, clothing and food by three. As a church-going Christian whose faith is vitally important to her, she thought it was God's plan and never considered abortion. But at her next appointment, Hannah learned that one of the babies had stopped growing, and there would be just two babies, both girls. Eisenhower High School's perfect couple sent the gossip machine into overdrive. "I don't know how people found out, but â¦ like everybody knew by the next day," said Hannah. The girl whom no one would have expected to get pregnant quickly learned that her popularity came at a price. When I walk down the halls, I see people going 'Is that the girl, is that the girl,' and then I see them look at my stomach ... I have an audience of over 2,000 people and everybody's watching," Hannah said. Hannah is not alone. According to the National Campaign to Prevent Teen and Unplanned Pregnancy, 47.8 percent of all high school students report they have had sexual intercourse. At Eisenhower High about 20 students become pregnant each year, principal Stacey Locke told ABC News. To help the students deal with the challenges that expecting and parenting teens face, the school provides a net of support to make sure students graduate and succeed, she said. Teen Pregnancy: 'A Huge Detour' "We provide an all-around support system in every facet of our school so that they can continue to get their education, provide for their child, and be successful when they leave," Locke said. Hannah's father, Daniel, while very supportive of his daughter, said her experience should be taken as a lesson, not an example. "This is hopefully going to be a wake-up call to a lot of families that have young girls that are in love and feel that they've met their soulmate and are going to be intimately involved with them," he said. Let this be a wake-up call to the parents and take the precautions so this doesn't happen to other families. Hannah, who missed her prom because of the pregnancy, is now facing that "wake-up call" herself, feeling overwhelmed and alone. The hardest part now is like, what am I going to do now? There's a huge detour in my life," she said. I can't do everything I wanted to do. I think about that every day. Hannah said it's hard knowing that she might not be with Taylor the rest of her life -- the two are currently apart. But he will always be the father of her girls, she said. Taylor wants them to be in sports. He talks about how he wants to coach their basketball; he wants them to do gymnastics and all this stuff. I know he wants to be involved," Hannah said. At the start of June, Hannah's thoughts on the future were overtaken by present reality. As her classmates and Taylor were crossing the stage to get their diplomas and ending one chapter of their lives, Hannah was beginning another. On June 4 she gave birth, two months prematurely, to Mya Danielle and Braelyn Marie. With her babies in her arms, she says there's only one thing she knows for sure. "I'm going to be a strict mom," she said. My kids aren't going anywhere. And they're not going to have boyfriends, ever. Well, at least not in high school. Unexpected Turn Early last week, on June 16, Hannah's story took one more unexpected turn. One of her twins, Mya Danielle, died. Early infant death is more likely to occur with teenage mothers -- and the younger the mom, the higher the risk. About one in 250 babies born to teens Hannah's age die in the first four weeks of life, compared with one in 300 for moms in their early 20s. Babies born to moms ages 10-15 have an even higher chance of early death.