sounds like an umbilical hernia. I have one but luckily it has not hurt in a long time. If it is your doc can tell you quickly. It requires surgery and you will not be able to do anything for two weeks and then you cant lift anything over 10lbs for another month. I decided not to have surgery last summer because i was no longer in pain. obviously you're going to wait till after your show to go to docs and determine what it is and make your decision from there.