The younger sister of Britney Spears gave birth to a baby girl named Maddie Briann in June 2008.
Jamie Lynn revealed in a new interview that she never expected to get pregnant.
"It was 2007. I had been on a Nickelodeon show, Zoey 101, and after we wrapped shooting, I just wanted to go home to Louisiana and finish high school, be a cheerleader, all that," she told Glamour.
"Then I found out I was pregnant," she continued. "I was young. I was in love. I was like every other teenager, except I had this last name. And I made a decision that is forever my decision."
The actress went on to admit that she never sought out birth control because she was "scared to go to the doctor".
"I was on a Nickelodeon show, and it felt especially embarrassing to ask someone to put me on birth control," Jamie Lynn said.
"I did feel responsible for the young girls and the mothers who I probably confused and let down. I apologise for that. But I wasn't trying to glamorise teen pregnancy.
"I hated when [the tabloids] said that. Everybody is dealt a hand of cards. It was my choice to play them the way I played them. But the hateful comments hurt."
Jamie Lynn, who split with Maddie's father Casey Aldridge in 2009, confessed that having a child together put a strain on the couple's relationship.
"It's sad because my and Casey's love had to turn into an adult relationship so quickly," she said. "There's a slim chance of two young people making it through high school and all that drama, but making it as parents?
"We tried. We really wanted to do it right. We loved each other. I will love him as Maddie's father until the day I die."