Have A Hard Lump In Lower Right Cheek Inner Cheek

Have a hard lump in lower right cheek inner cheek tissue. I chew on cheeks and play wrestle with my son which has play punched me in same area. It's been a couple of months and it's stayed about same size. It's sort of near tooth had root canal on and dental infection. Any idea what it could be? I can't see it or really feel it with finger but can feel it with tongue. Just worries me.