Credit: Butters/Masso/Splash News Online

Forget Hilary Duff and Jennifer Garner: Does Cameron Diaz have a bun in the oven?!

The actress -- who turns 39 next week -- rocked short shorts, sneakers and sizable pregnant belly in Atlanta on Tuesday. No, Alex Rodriguez's love isn't going to be a mom just yet: She was donning a pregnancy suit for her role in What To Expect When You're Expecting, which costars Jennifer Lopez.

Although Diaz has bonded with love Rodriguez's daughters Natasha and Ella, she's up in the air about becoming a mom herself.

"I never say never," she said in 2009. "I don't know what's going to happen. I could end up adopting half a dozen kids, or I could end up being the next 'Octo-mom' -- who fricking knows!"

Tell Us: Would Diaz make a good mom?