The Black Eyed Peas singer and her actor husband Josh both posted snaps of the adorable infant on their Facebook pages.
Josh shared a snap of his contented, sleeping son with the words "Axl Jack Duhamel Day 1 #paparazziyoucanleaveourhousenow."
Meanwhile proud first time mum Fergie posted an image of her baby boy wearing earphones. She accompanied the picture with the caption, " Axl Jack Duhamel. Day 2 of life. Hearing test complete. All systems go."
The two photos came as a surprise to fans of the proud parents. On Monday, Josh gave no hint as to when they would introduce their son to the world. "Right now we just want him all to ourselves," the All My Children actor tweeted.
Axl was born via a scheduled C-section on 29 August and weighed in at 7 pounds and 10 ounces, their rep told PEOPLE.
It is thought that the baby's unsual name was inspired by Guns N' Roses rocker Axl Rose.
The new mum , 38, is a big fan of the band and even performed Sweet Child O' Mine with guitarist Slash during the Black Eyed Peas' Super Bowl halftime show in 2011.
Back in May, the I Gotta Feeling songstress spoke about what starting a family meant to her and Josh.
"We're thrilled," she said. "When that moment occurs to you, there's going to be a human being growing inside of you... it's reality. It's amazing ; we're thrilled."
This summer, Fergie, whose real name is Stacy Ferguson, applied to change her name legally to Fergie Duhamel. That way she and her baby will have the same surname.
Love blossomed for the pair on the set of his TV series Las Vegas when she had a cameo appearance. They married in 2009.