I HAVE A SWOLLEN LUMP FROM MY ELBOW TO MID

I HAVE A SWOLLEN LUMP FROM MY ELBOW TO MID ARM SWOLLEN BUT NO PAIN ALSO MY ARM IS HEAVILY BRUISED FROM ABOVE MY ELBOW HALF WAY TO MY ARM PIT AND BRUISED UP TO ABOVE HALF WAY TO MY WRIST -- i HAVE NOT BUMPED IT OR DONE ANYTHING i THINK COULD WARANT THIS i am on warfrin but had it checked on monday and it was 3.0