Bristol Palin on Her Failed Safe Sex Practices with Levi Johnston

Bristol Palin sat down with Dr. Drew Pinsky during a special on HLN Thursday, dishing on the intimate details of her highly publicized relationship with the father of her child Levi Johnston.

In her new book Not Afraid of Life: My Journey So Far, Bristol explains how she became pregnant in spite of claims that she and Levi practiced safe sex and she shared the revelation with Dr. Drew, saying, "I was on birth control when I got pregnant and I had stopped taking it for, like, three or four days ... It wasn't used effectively."

Bristol described her experience with teen pregnancy as "the hardest thing that I have ever had to go through," which is why she wants to educate teen girls on the proper ways to practice safe sex.

"I'm not out there saying 'Don't have sex,'" said Bristol, explaining that she does not advocate abstinence for teens. "I'm just saying that birth control needs to be used effectively each and every single time."

Bristol did admit that she wishes that she had waited to have sex until marriage, saying that losing her virginity to Levi was a violation of her moral code.

As far as Levi's relationship with his son Tripp, Bristol says that he's not involved in the infant's life and that she no longer wants to build a family with her former fiance.