Is it?

I've had a small lump inside my lower lip for a year now. At first it would blister but now it is hard and white with a hole in the center. Looks like it has a rim. I chew it a lot and it's stayed about the same size, maybe a little larger with time. last couple of days after a chewing on it, the lump swelled and now has a crusty lid on the hole. Going to the Doc next week but I'm still sweating it!