The "This is 40" actress' son Noah Shannon is helping to keep the one-time Sexiest Woman Alive in check these days, Fox told E! News.
"The whole thing has been overwhelming because I didn't realize you could love something so much, and I know people always say that but I love him so much it hurts," Fox said, "and it's an interesting feeling to have because I never felt that before."
"He's getting to that place where he's smiling and he's almost ready to laugh, and I can't wait for that baby laugh that almost makes you feel like you can fly, like your heart's going to explode."
Fox, 26, and husband Green, 39, welcomed baby boy Noah into the world on Sept. 27 after keeping a relatively low profile during her pregnancy.
And already, in the just over two months since Fox has taken on the role of "mom," the once-racy actress is seeing a shift in the way she approaches life - and her work.
"It changes your perspective about being overly sexual in a film when you have a baby," she told the UK’s Mirror in a recent interview. "I'm going to be more cautious about choosing films because I'm already thinking about when he's in school and his friends are going to be showing him my photo shoots with me in a bikini and he's going to be horrified."
Even Noah's name is a Biblical reference, Fox explained.
"I went through a stage in my early 20s when I was very rebellious against how I was raised and I wasn’t worried about faith or religion but now, maybe because of getting married and wanting to have a family, I've come back full circle," she told the paper.