Small movable painless bump on right side of neck close to my jaw. had it for a few months. i have a chronic mouth infection on same side. lymph node?

Lymph node: Yes, you are most likely describing a reactive lymph node. They react to something like an infection. By reacting, they usually get larger. When the infection is gone, they often get smaller, but sometimes stay enlarged. As long as it is moving around and not causing any particular problems, best to just keep a close eye on it. If it changes or becomes immobile, get it checked.