Michael Phelps is officially a dad! On Saturday, the Olympic swimmer took to Instagram to share the exciting news, writing, "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!!! #boomerphelps @boonestudios." Along with the sweet an**uncement, Michael uploaded an adorable black-and-white photo featuring his fiancée, Nicole Johnson, and their little bundle of joy. You may remember Michael revealing Nicole's pregnancy news back in **vember with a supercute shot on social media. Congrats to the couple on their growing family!