Olympian Michael Phelps is a daddy!

The swimming sensation and his fiancee, Nicole Johnson, welcomed a baby boy together on Thursday, May 5. Two days after Johnson gave birth, the athlete posted a proud papa photo showing off his wee one -- whom the couple named Boomer Robert Phelps.

The black-and-white photo features the shirtless swimmer and his bundle of love, as the adoring new mom rests in a hospital bed. Along with the Instagram photo, the 22-time medalist wrote, "Welcome Boomer Robert Phelps into the world!!! Born 5-5-2016 at 7:21 pm !!! Healthy and happy!!! Best feeling I have ever felt in my life!!!@nicole.m.johnson and Boomer both healthy!!!"

Now that's what we call a baby boomer -- heyoh!

The engaged twosome announced their baby news on November 18, 2015 via Instagram.

At the time, Phelps posted an Instagram of him and his bride-to-be in front of a pool with the caption, "We found out 8weeks ago we were expecting... Today we're over 12 weeks and it looks like we're having a boy!!! #babymp #mp #lifeabouttochange#mpswim"

Since making the announcement, Phelps has gushed about being a father.

The superstar told Us Weekly in March, "One of the coolest things about being a father going into Rio is that our firstborn has the chance to see my last race ever." He continued, "I think that's something that'll be really special that we'll be able to share stories with him, you know, from the time he gets old enough to realize, and I'm excited to have a lot of photos and just to share the moments and memories with him growing up as a kid."

Aww! We love that!

Phelps is currently training to compete in his final Olympic games this summer in Rio de Janeiro, Brazil. The Summer Olympics begin on August 5, 2016, on NBC.