What Causes Bruising On Legs Following DVT?

Hi, may I answer your health queries right now ? Please type your query here...hello I have several large black bruises appear on my left arm I have suffered from dvt in the past in both legs and was on 9mg warfarin and heparin injections I am leg conscious all the time and take an aspirin a day 75mg to stop blood clotting I am worried about the bruising as they take ages to disappear use heparin gel cream as advised by doctor what is causing them please