Mole okay by derm, but worried! Details and pics inside. (photos)

I had this mole on my leg for at least 2 years (probably longer). It is about 3x2mm. Derm check it out (w dermatoscope), said it was OK and there was a hair follicle inside and hence the color irregularity. Few days ago something from that mole has come off revealing a hole in the middle! It didn't bleed, didn't itch, no pus. I got anxious and scratched and pressed, and next day there is a dark brown scab. Attached are pics before and after. Does this resemble melanoma??? Do I have to worry???