What baby? Not only did the singer (a.k.a. Sasha Fierce) stay true to her diva-licious style throughout her pregnancy, but she also had tongues wagging when she showed up to hubby Jay-Z's N.Y.C. concert on Feb. 6 in a tight ruched red dress mere weeks after the Jan. 7 birth of daughter Blue Ivy. "I feel more beautiful than I’ve ever felt,” the superstar told PEOPLE.