Nearly three months after baby Noah's Sept. 27 birth, Megan Fox and Brian Austin Green still haven't released any photos of their little bundle of joy. But according to Fox, the tot is basically a miniature version of her husband.

"He looks, I would say, 70 percent like Brian," the new mom tells Ellen DeGeneres in an interview airing Wednesday, Dec. 19. "He was his identical twin when he came out [but] recently he's been getting chubbier and everyone's like, 'Oh, he's so chubby -- now he looks like you.'"

"I don't know how I should take that," she jokes.

The super-slim This Is 40 star -- already stepmom to Green's son Kassius, 10, from his relationship with actress Vanessa Marcil -- also chatted with DeGeneres about how actress Reese Witherspoon unintentionally helped her deliver Noah in secret.

"She went into labor the day before I did, and all of the paparazzi followed her to Santa Monica. So when I went into labor, I went to Cedars [Sinai Medical Center in L.A.], and nobody cared or knew I was there," Fox explains. "So I got in and out. I left the next day and nobody knew. It was a big secret for three weeks."

It might have stayed a secret even longer if the proud mom hadn't taken to her own Facebook page to announce the happy news.

"We are humbled to have the opportunity to call ourselves the parents of this beautiful soul and I am forever grateful to God for allowing me to know this kind of boundless, immaculate love," the actress wrote. "Thanks to those of you who wish to send your positive energy and well wishes."

This article originally appeared on Usmagazine.com: Megan Fox: Baby Noah Looks "70 Percent" Like My Husband Brian Austin Green