hi, on the left side of my mouth just below my second back tooth, i have a around about 2 cm red lump i have had it for about 1 week now and was normally not painful, but yesterday it started acing and today my tooth that it is under has been pushed higher ( feels weird to bite down ) and it hurts when putting pressure on it, it is a aching pain that is constant, also i am a smoker so could it be cancer?