Depends on your skin if it will close up, if you have sensitive skin it will most likely close up faster...i've had my ears peirced 6 different places and never wear earrings...i got my bottom holes done when i was three and didn't wear earrings from the time i was 4 til i was 17 and they were fine, i also got my upper ear done a few years ago and played softball with it out the day after i got it done, i would take it out for a game or whatever and put it back in a few hours later...it hurt like a b**ch but i still have the hole
another thing you can do is go to a tattoo parlor or claire's or hot topic might also have them...but look for a clear belly button ring...when i got my last piercing i put a clear earring in there and never got busted with it...plus the clear ones are like plastic and bendable so it would be alot harder to be ripped out while you were cheering...
some of my teammates would slide on their stomachs like 2 weeks after they got their bellys pierced so i think you should be fine!