Brian Austin Green addresses 'crazy' Megan Fox pregnancy news

Brian Austin Green is in shock over the "crazy" news his estranged wife Megan Fox is pregnant with their third child.

Although the 29-year-old actress filed for divorce from the former Beverly Hills, 90210 star in August (15), the pair now have something to celebrate, as their sons Noah, 3, and Bodhi, 2, will be welcoming a sibling in a few months.

Megan debuted her burgeoning baby bump on Monday (11Apr16) while promoting Teenage Mutant Ninja Turtles: Out of the Shadows at CinemaCon in Las Vegas and Brian is feeling all sorts of emotions about the news, confessing the situation is blowing his mind.

"You know, nothing is planned,” he tells People.com. “None of them (the children) are ever planned. You kind of just go with it."

“At my age, to be having three babies, is crazy,” he laughed. “I’ll be 43 this year.”

On Friday (15Apr16) the actor attended the Toyota Grand Prix of Long Beach Celebrity Race, which was hosted by the Verizon IndyCar Series. And during the revved up event, he revealed fatherhood has changed his perspective on his race car driving hobby.

"It used to be just the rush of doing it,” Brian shares. “You know, it’s a different feeling, a different rush than you are used to, and now that I’ve got (laughs) all the kids that I have it’s like, ‘Yeah, this is fun…’ ”

He added with a laugh, "It’s important that I live."

When news Megan is expecting her third child grabbed headlines, the Transformers star showed she could still maintain her sense of humor despite being fiercely private about her family life by posting a cheeky snap on Instagram Tuesday (12Apr16).

"#notthefather," she captioned a photo of herself with co-stars Shia LeBeouf, Will Arnett and Jake Johnson, in response to reports that one of them fathered the child she is currently carrying.