LOS ANGELES: Olympic swimming superstar Michael Phelps is a proud father of a baby boy, announcing the birth of son Boomer on Saturday via Instagram. Phelps said fiancee Nicole Johnson gave birth on Thursday night, and posted a picture of himself cradling the infant at Johnson’s bedside. “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!!!,” Phelps wrote. Phelps, whose 22 Olympic medals include 18 gold, is gearing up for a Rio Games challenge. He’ll compete at the US Olympic swimming trials in Omaha June 26-July 3 and has said he hopes to be in Rio with Johnson and Boomer there to cheer him on.