I had to have mine fixed within a week or 2 of noticing it. During that time it grew from a golf ball to a fist and got to be excruciating. If its an inguinal hernia (which it sounds like) the risk of continuing training is that when its protruding out of your diaphragm your intestine can be strangled and lose blood flow and die.
Sorry to be the grim reaper papa but go to the doc and get it checked.