IF Gisele Bundchen is pregnant, she’s got a great poker face. The supermodel gave no hint of the happy news as she left an OB/GYN office on Park Avenue yesterday with her husband, New England Patriots quarterback Tom Brady, who was equally stone-faced. The couple (right) wed in February in LA, after dating for more than two years, and married again last month in Costa Rica with Brady’s son, John Edward Thomas Moynahan, present. Asked if Gisele was with child, a spokesman at IMG said, “We have no comment on our clients’ personal lives.”