Is A Hurting Mole A Blood Blister Or Something More Serious?

I have what looks like a mole or possibly a blood blister right under my butt cheek

It has happened like once or twice before.Just hurts out of nowhere. Doesnt actually bleed or bust and usually goes away on its on. Is this a sign of melanoma or is it a blood blister. I know this sounds silly, but I never notice a mole there until it hurts like this. Which is why I feel like it may just be a blood blister