I have a hard lump in the bottom area of my gum, on the right hand side, close to the in the vestibule area. I ve had it for about 3 months, it is very small, smaller than a pea and it is smooth. It has not changed size or colour and is the same colour as the rest of the area. I think I developed it one day when I was brushing my teeth and the toothbrush slipped and put pressure on that area. The lump is in the crease area. Thank you.