I've had a mole on my back for 2 years. Looked like a pimple at first, kind of a reddish brown color. After picking at it for a while it scabbed and grew back slightly darker, again a few months ago I accidently knicked it, it scabbed and now looks darker. Could the darkening be from the trauma of being scratched off? It doesn't look to me that it has grown, doesn't itch, hurt, bleed or any of that scary stuff. It is an odd shape though, kind of like a teardrop.