Megan Fox has just announced she's expecting baby #3.

American actress Megan Fox has just announced that she is pregnant.

29-year-old Fox made the announcement yesterday when appearing at CinemaCon in Las Vegas wearing a tight fitting dress that put her growing bump proudly on display.

This will be the third baby for Fox, who is mother to sons 3 year-old Noah and 2 year-old Bodhi with her ex-husband, Brian Austin Green (or BAG, as we here at MM HQ like to refer to him).

Megan Fox at CinemaCon with Will Arnett (right). Soure: Getty Images.

While Fox and Green announced their separation in August last year, ending an 11 year long relationship, they have been seen spending time together of late. So it could be a reconciliation and a third baby on the way or it could just be parents parenting together well and a single mum getting on with her (sex) life. Who knows?

If there's one thing we can put our bets on though, it's that the Hollywood rumour mill will be on high alert until Fox confirms the paternity.

Fox with ex-husband Brian Austin Green in 2014. Source: Facebook. 

Fox was on duty last night with actor and comedian Will Arnett, promoting their upcoming film, Teenage Mutant Ninja Turtles: Out of the Shadows, the second in the remake series.

Fox has previously spoken about her experience of being pregnant with her youngest son Bodhi during filming of the first Teenage Mutant Ninja Turtles, so it looks like baby number three is well-timed.

Congratulations Megan! We hope it's a smooth sailing and happy pregnancy.