It could be an oral infection of some kind, caused by normal bacteria, or maybe you irritated it with food, toothpaste, mouthwash, etc.
Aj
thanks i will....so u think that this is not an std right? do u know of anything else it could be
It doesn't sound like an std, and any bump caused by an std wouldn't last this long. Oral hpv is very rare, so I wouldn't even think that.
Why not get it checked by a doctor or dentist?
AJ
Just to add...it is very smooth and sometimes hard to tell its there.