I scratched off a raised mole last week. it bled then healed and left a dark pigment spot. would the mole grow back if it was a melanoma? i'm worried ?

All moles have a blood supply which would cause bleeding when scratched off as yours was. The dark spot left may be pigment from original mole or post-inflammatory pigment from the scratching/healing process. At your young age a melanoma would be quite unlikely unless perhaps you have had an excessive amount of sun exposure or a heavy family history of melanoma. But see Dr if bleeds/regrows