Was hit in hamstring and now have numbness and tingling in lower leg and knee a week later? Any ideas?

I was playing kickball and was kicked or hit in the back of my leg (hamstring) and it was painfull that day but went away over the weekend. I now have bruising in around my knee pit and my lower leg and toes have been numb and tingling for the past few days. It feels like I have constant leg cramps and it is driving me crazy. Could I have burst a major blood vessel or pinched a nerve or is it just a bad bruise that is finally showing?