Britney Spears and Justin Timberlake famously dated from 1999 to 2002, and now, in her upcoming memoir, "The Woman in Me," the pop star alleges that during their relationship, she became pregnant.
Spears says that after Timberlake learned the news, he convinced her to have an abortion.
"It was a surprise, but for me, it wasn’t a tragedy," Spears wrote in an excerpt shared exclusively with People. "I loved Justin so much. I always expected us to have a family together one day. This would just be much earlier than I’d anticipated."
She continued, "But Justin definitely wasn’t happy about the pregnancy. He said we weren’t ready to have a baby in our lives, that we were way too young."
Spears writes that in the end, she decided to go along with Timberlake's wishes.
Britney Spears and Justin Timberlake first met while filming "The All New Mickey Mouse Club." (Photo by Jeffrey Mayer/WireImage/GettyImages)
"I’m sure people will hate me for this, but I agreed not to have the baby. I don’t know if that was the right decision. If it had been left up to me alone, I never would have done it. And yet Justin was so sure that he didn’t want to be a father."
The singer confessed, "To this day, it’s one of the most agonizing things I have ever experienced in my life."
Reps for Timberlake did not immediately respond to Fox News Digital's request for comment.
FILE-Britney Spears performs at 102.7 KIIS FM's Jingle Ball 2016 at Staples Center on December 2, 2016 in Los Angeles, California. (Photo by Jason LaVeris/FilmMagic/Getty Images)
Spears and Timberlake met while appearing on the Disney Channel's "The All New Mickey Mouse Club" when they were children. Though they were both barely preteens at the time, Timberlake later told GQ, "I was in love with her from the start. I was infatuated with her from the moment I saw her."
After the show ended, they went their separate ways, but they soon found their own respective paths to pop superstardom – and back to each other.
Justin Timberlake and Britney Spears have spoken kindly about each other after their breakup. (Photo by Denise Truscello/WireImage/Getty Images)
In 1999, the year Spears released "… Baby One More Time" while Timberlake was riding high as the heartthrob in immensely popular boy band NSYNC, the two began dating. In 2002, when she was 20 and he was 21, they broke up.
Spears went on to have two children, sons Sean, born in 2005, and Jayden, born in 2006, with ex-husband Kevin Federline.
Timberlake shares sons Silas, 8, and Phineas, 3, with wife Jessica Biel.
Emily Trainham is an entertainment editor for Fox News Digital.