sudden blue bruise on my outer left knee/leg. No injury, it just hurt and I grabbed it and litterally within minutes I saw the bruise travel along my veins in my leg. My husband traced the bruise thinking it was a possible blood clot before bed last night. This AM the very blue bruise has turned very purple and black. It has gone outside the traced outline and looks like its following along my veins lighting up blue...it has now gone past my leg and seems to be crawling up my thigh...any ideas???