Megan Fox Reveals How Reese Witherspoon Helped Her Keep Baby Noah's Birth a Secret

This Is 40 actress hits Ellen for a sit-down airing Wednesday

Megan Fox has baby on the brain.

The new mom, who was convinced she was birthing a vampire during her pregnancy, dished to Ellen DeGeneres about how Reese Witherspoon helped take the attention away from her delivery of baby Noah.

In a sit-down on Ellen, Fox said, "[Reese] 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 [medical center] and nobody cared or knew or was there, and so I got in and out. I left the next day and nobody knew and it was a big secret for three weeks."

Fox was a little less candid, though, when DeGeneres asked if Noah looked more like her or her hubby Brian Austin Green, answering the question but not showing any pictures of her tiny tyke.

"He looks, I would say, 70 percent like Brian," Fox said. "He was his identical twin when he came out, and recently he's been getting chubbier and everyone's like 'Oh, he's so chubby; now he looks like you,' and I don't know how I should take that." 

The 26-year-old This Is 40 actress and Green have become quite the secretive pair, keeping news about their son's birth under wraps for nearly a month. 

Fox's interview on The Ellen DeGeneres Show is scheduled to air on NBC Wednesday.

(E! and The Ellen DeGeneres Show are both part of the NBCUniversal family.)