What Causes Bleeding From From A Post Surgery Scar Indicate?

I have a scar that has been there for five years from surgery in which an ovary was removed. It is started to look different in color (it is purplish now when it was whitish before) and it has a nearly perfectly circular opening which is bleeding, however the blood is darker than normal. It is not painful and the blood colored discharge is not enough to be overwhelmed by a band-aid. Should I be concerned about the changes in this scar?