Britney Spears has announced she is pregnant with her third child, months after the end of a strict conservatorship which she claims forced her to use birth control.

The pop star, 40, announced she is expecting a baby with fiancé Sam Asghari in an Instagram post.

Sharing that she noticed that she had started gaining weight after a recent trip to Maui with the 28-year-old fitness trainer, Spears wrote, “So I got a pregnancy test … and uhhhhh well … I am having a baby.”

She is already a mother to sons Sean, 16, and Jayden, 15, from her previous marriage to Kevin Federline.

In November, she was freed from a 13-year-long conservatorship which controlled her life and money, after a Los Angeles judge ruled it was “no longer required”.