I have a dark bruise on the back of my thigh right above my knee . the bruise is about the size of my fist and i have done nothing to recieve it. it merely showed up. the edge is about an inch wide with a mix of burgandy, dark purple, and blue. the center however is a small square inch circle that is my normal skin color, maybe a bit whiter. it has been here for four days but because of the location i am not really sure if it was here before this or if it is changing. the center has a bump in the middle that appears to occupy most of the white area.