Confused? Well, the actress, who welcomed her second son with husband Brian Austin Green in February, told the host that whenever she appears on the show, she ends up having some baby-related news to share.
"The first time I was here, I was pregnant and no one knew it," the "Teenage Mutant Ninja Turtles" star said. "And then the second time, I just had my baby, but I got pregnant. So you're like a fertility good luck charm. If you want to get pregnant, come see Ellen."
"My show is an aphrodisiac," DeGeneres quipped.
Which raises the question: Is she already thinking about baby No. 3? We're not sure, though we wouldn't be totally shocked.
Fox's sons, Noah and Bodhi (or as she identifies them: "the one with the lips" and "the little chubby one," respectively), are only 16 months apart, and neither pregnancy was planned, she said.
"We can't let Brian near me anymore," she joked, " 'cause every time ... "
OK, you're hot. We get it.
The comely couple wed back in June 2010, and the 27-year-old beauty explained that the second pregnancy came at a busy time for her.
"I got pregnant with Bodhi two weeks into filming 'Ninja Turtles,' " she said. Starring in the live-action film required a lot of running and jumping, which didn't help too much with her morning sickness.
"Anyone that's been pregnant knows your first trimester can be pretty rough and you're nauseous all day long," she said. "So I spent the whole shoot, basically, the producers would come see me in the morning in the makeup trailer and I'd be clinging to a box of saltines. ... I was constantly on the verge of vomiting."
The latest trailer dropped last week, and the cast includes Will Arnett, Whoopi Goldberg, Tony Shalhoub and Mos Def. And, no, those guys don't play the famous pizza-loving mutant quartet. (Johnny Knoxville, Alan Ritchson, Noel Fisher and Pete Ploszek do, voicing the computer-generated versions of the vigilante reptiles.)