I Scratched My Back Cause It Itched. Didnt Think There

i scratched my back cause it itched. didnt think there was a mole there, but maybe, anyways it bleed for about half an hour . quite a bit have a four inch circle on my white dress and many tissues used i was driving home. have band aid on now used cayenne to stop bleeding. should i be concerned? will it start bleeding again at night when i sleep/