UPDATE: Megan just confirmed her pregnancy and addressed the baby daddy speculation with a hilarious Instagram snap.
Next to a photo montage of her posing alongside Shia LaBeouf, Will Arnett and Jake Johnson, she simply wrote the hashtag, #notthefather.
Not pictured: Brian Austin Green.
Megan Fox is pregnant!
The actress showed off her budding baby bump on the red carpet for the CinemaCon 2016 Gala Opening Night event at Caesars Palace in Las Vegas on Monday. Multiple sources likewise confirmed the actress' pregnancy news to E!.
But, Fox definitely surprised everyone as she showed off her bump in a curve-hugging LBD -- and her belly was most visible when she posed for photos on the red carpet with her "Teenage Mutant Ninja Turtles" costar Will Arnett.
The "Transformers" star -- who filed for divorce from husband Brian Austin Green last August -- already shares two children with the "Beverly Hills, 90210" alum, sons Noah, 3, and Bodhi, 2.
Though Green filed documents in September seeking spousal support from the 29-year-old beauty, the two have remained on good terms for their children. They've even been spotted on numerous family outings together this just year.
We caught up with Megan just a few weeks ago -- where she hid her belly in a loose-fitting top -- and talked to her about her kids and whether they'll ever watch her movies.
Are you surprised by Megan's red carpet baby bump debut? Sound off below and check out the gallery above to see even more expecting stars!