Lip Infection?

About 4 months ago my lower lip started to swell up. It was mainly in one spot that is swelled and the rest was just a little puffy and tender. After about a week or two it went away. Just 4 days ago the same thing happened except a have a small sore on the inside of my mouth just below the part of my lip that is swelling (exact same spot as last time). I decided to go to minor er incase is was an allergic reaction and the docs were closed. She told me she thinks it is herpes simplex 1 and wrote me a rx and sent me on my way. I have no cold sore, no sores on the out side of my mouth or anything. Not one thing I have looked up seems similar. Any one know what it could be or have any advice?? Thank you!

[TGuth]

I have been searching online and I think it might be a canker sore. Its a small sore in my mouth with a white center... Has any one else had a canker sore??