It could be an infected tooth. You should probably see your Dentist. Take care. Remar
I would have thought that too, but my teeth are in excellent condition and the knot doesnt hurt.. at all..
I would still go to the dentist to have it looked at. You could have a cavity under the gum line where you can't see it. That's what happened to me. The cavity was under my gum line and I got a painless knot right above that tooth.
This could be something totally different but dentist's know about the whole mouth. You may have cut your gum on a piece of hard food and it caused an infection. Have it checked out and let me know how your doing. Take care. Remar