A red sore on cheek? Not painful, not a canker sore, what could it be?

Have you ever had anything similar? I've had canker sores before and they're annoying but overall nothing bad. I never had something like that though. It's a small, round red sore that doesn't look very good. It's not painful or sensitive but is slightly raised. I don't know what doctor to even see about that and I immediately ume the worst. The sore is on the inside of my cheek and I have to mention I had wisdom teeth extraction a week ago but just noticed it now, I don't think it was there a couple of days ago, as I obsessively check my mouth and stitches. Help?