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Alaska Gov. Sarah Palin's 18-year-old daughter, an unwed mother, says teenagers should avoid having sex.

However, Bristol Palin acknowledges that abstinence is "not realistic at all." She commented during a two-part interview recorded for FOX News Channel.

Just days after the governor was named John McCain's running mate on the Republican presidential ticket last year, she announced her daughter was pregnant. Bristol Palin gave birth Dec. 27 to a boy named Tripp.

Bristol Palin said her son brings her so much joy that she doesn't regret having him at all. She's engaged to the baby's father, Levi Johnston, and said her fiance sees their son every day.

TRANSCRIPT: Read Greta's interview with Bristol Palin

"He's a really hands-on dad," she said. "He's just in love with him as much as I am."

Bristol said telling her parents she was pregnant was "harder than labor." Levi and her best friend went with her to break the news.

"I was just so sick to my stomach. And so finally, my best friend just, like, blurted it out," she said. Bristol also said it bothered her to hear that many people thought her mother was making her have the baby, when it was her own choice.

The governor also appeared in the interview, recorded Saturday in Fairbanks.

She said she was proud of her daughter, "wanting to take on an advocacy role and, you know, just let other girls know that this is — it's not the most ideal situation, but certainly, make the most of it," Sarah Palin said. "And Bristol is a strong and bold young woman and she is an amazing mom. And this little baby is very lucky to have her as a mama. He's going to be just fine."

Part one of the interview aired Monday night and the second part was scheduled for broadcast Tuesday night.

The Palins were in Fairbanks to watch the governor's husband cross the finish line of the 2,000-mile Tesoro Iron Dog snowmobile race. Todd Palin, whose team came in sixth, is a four-time winner of the world's longest snowmobile race.

Dr. Keith's Blog: Bristol Palin, Jamie Lynn Spears - The Brave New World of Teen Mothers