Britney Spears is celebrating her memoir The Woman In Me breaking a major record just a day after its release.

In an Instagram post, she celebrated her autobiography becoming the “highest selling celebrity memoir in history.”

As a way to celebrate the milestone, the Pop Princess posted a short reel with the book cover and the words “My story.”. It’s my story. On the background, the words “At last” appear.

Oops I Did It Again singer wrote, “It’s happening!!!” to her 42 million followers. It’s only day 1 and my book is already the most popular celebrity memoir in history! I would like to thank the fans who have been so supportive! Love you all!

Britney shared only a small portion of the book, and avoided discussing the chapters about her family as “it was too painful for her to talk about.”

Her memoir covers major life phases including her 13-year conservatorship, fame, marriages to Kevin Federline and Sam Asghari, and the abortion she had during her Justin Timberlake relationship.

The DailyMail.com reports that the NSYNC alum didn’t reach out to Britney after the revelation, but was shocked to learn that she discussed “such deeply personal matters.”