A few days ago I was driving and I felt a swelling in my mouth with a bump. A small white bump. It did not hurt. A couple of days later I guess as I was bothering it, it started to hurt. I also noticed that the white spot had grown more flat and larger. Prior to this I did have some pain under the white jaw. I do have periodontal disease but wanted to know if it is related to an abscess or if it is a canker sore.