The book features several shocking reveals about her past relationship with Justin, which spanned from 1999 to 2002.
Ultimately, she decided not to have the baby – expressing some level of regret.
“If it had been left up to me alone, I never would have done it,” Britney, 41, wrote.
“And yet Justin was so sure that he didn’t want to be a father.”
The pregnancy is just one of many big bombshells about her relationship with the Trolls voice actor in her book.
That’s not all that she plans to talk about either.
In addition to opening up about the N*Sync singer, Britney will discuss raising her sons Sean Preston, 18, and Jayden James, 17, with ex-husband Kevin Federline, her career highs and lows, her family, and more.
Here’s a look at some of the more shocking relationship bombshells Britney makes in The Woman in Me.
The Circus singer further shared that her pregnancy “was a surprise, but for me, it wasn’t a tragedy.”
She claimed that she wanted to start a family with Justin at that point, though she found herself pregnant sooner than she expected.
“I loved Justin so much. I always expected us to have a family together one day,” the book reads.
“This would just be much earlier than I’d anticipated.”
Britney went on to write in her memoir: “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.”
It’s unclear from the excerpt, at what point in their relationship the pregnancy occurred.
In The Woman in Me, the Louisiana native said that the abortion was “one of the most agonizing things I have ever experienced in my life.”
Britney wrote about meeting Justin, revealing that it all started when they were Mouseketeers on Disney.
The group, she writes, was divided into cliques that were divided by dressing rooms.
She and fellow pop princess Christina Aguilera were both younger and shared a dressing room.
Before long, she and Justin formed a connection despite the cliques.
Britney and Justin took their relationship from friendship to more during a group sleepover.
The Mouseketeer kids were playing a game of Truth or Dare when someone dared Justin to kiss Britney.
She wrote in her book that a Janet Jackson song was playing at the time when the musician-turned-actor “leaned in and kissed me.”
They weren’t a couple yet, however.
The Mouseketeers ended and Britney headed back to the small town she’s from in search of a simpler life.
“For a minute, I had to let normalcy win,” she wrote.
She couldn’t stay out of the limelight, however.
In 1999 she released her smash hit record Baby One More Time followed by Oops!…I Did It Again in 2000.
As she was thrust back into the industry, Britney and Justin found their way back into one another’s hearts.
Justin appeared on Total Request Live in 2002 to unveil the video for his single, Cry Me a River.
The lyrics and storyline in the video suggested that the song was about Britney.
It showed Justin and a blond actress dressed suspiciously like the songstress as she cheated on him.
The lyrics stated: “Told me you loved me / Why did you leave me all alone? / Now you tell me you need me / When you call me on the phone.”
Justin denied that the song was about Britney in an interview with Carson Daly, who hosted the music video show at the time.
“A lot of people have asked if the video is about her,” he said at the time, according to The Boston Globe.
“It’s not about her, it’s about me.”