isn't this a canker sore?
http://en.wikipedia.org/wiki/Aphthous_ulcer

oh wow i just read it and it doesnt seem like the thing ur talking about but i thought that is what a canker sore is.

whatever it is ive had the thing you've talked about and i was able to eventually peel it off, so i dont think it's anything to worry about, idk how to stop it from getting bigger.