found a bruise on my left breast . started out the size of a quarter. a week later it is double the size. it is not tender, just purpleish. the center (about the size of a nickle) is clear but the outer ring is definitely bruise colored. will make an appointment for doctor this week, but just wanted some ideas as to what this could be. no visible bite from amug. does not hurt. doesn t seem to be anythin in it, i.e., a boil .