Mouthing off

[davidada]

i have just discovered a painless but large blood blister behind my bottom back molar on the right hand side. Didn't have it this morning - I know this because I can feel it everytime i swallow spit (one of those bodily functions which is usually mercifully unconscious but is now driving me insane because the blister draws atention to it every time i do it).

Will it go away on its own? I'm not afraid of dentists but the tedium of making an appointment etc.