Britney Spears joyfully announced on Instagram on Tuesday that her book, "The Woman In Me," had become the "highest selling celebrity memoir in history."

With an official release of her much-awaited memoir on Tuesday, the 41-year-old singer of "Baby One More Time" exclaimed to her 42.3 million fans and followers, "It's happening!!!"

"My book is the highest selling celebrity memoir in history and it's only day 1 !!! Thank you to the fans who have been so supportive !!! Love you all !! #TheWomanInMe @gallerybooks @simonandschuster."

She uploaded a photo of the book cover and added a short reel that had the words, "My story. On my terms. At last."

Additionally, the audiobook version was made available, and Michelle Williams, an actress nominated for an Oscar, narrated it.

ALSO READ: Britney Spears Wants Family To Say 'She's Right' After Reading 'The Woman in Me'

TMZ also revealed earlier this month that Spears only taped a small amount of the book and refrained from reciting chapters about her family because they were "too painful to retell."

The celebrity discusses her 13-year conservatorship, her connection with her family, her rise to stardom, and her marriages to Sam Asghari and Kevin Federline in her memoir.

The celebrity disclosed that she had an abortion with Justin Timberlake in an excerpt that they were able to obtain. Before they broke up in 2002, the ex-couple dated from 1999 until that year. Later on, she got married to Federline, with whom she has two sons: Jayden, 17, and Sean Preston, 18. In 2007, their divorce was finalized.

The singer for the song "Mirrors" also has two children with wife Jessica Biel: Silas, age 8, and Phineas, age 2.

Right on the first day of its release, the book was put on sale. It is not clear if this means good or bad for Spears, but it certainly mean more people can get their hands on it. 

For years, a lot of people were waiting for this memoir to be released. While many celebrity memoirs are expensive, Spears' book at $23 instead of $36 is a good steal!

The kindle version is even priced at $16.99 only. 

Britney Spears has been in the public eye since she was a little child, but in the beginning of her career, she developed a carefully constructed public persona. The 41-year-old has experienced highs and lows in the public eye, but she hasn't publicly shared her thoughts on any of them.

She's laying everything on the line now.

Spears discusses her relationship with Justin Timberlake, her ascent to pop success, her family strife, and her decision to shave her head in the book.

Although Spears's disclosures, such as her abortion while dating Timberlake, have garnered media attention and may have caused controversy, she has expressed her gratitude for sharing her life experiences. 

ALSO READ: Britney Spears Details Suffering While Married to Kevin Federline: So Many Red Flags 

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