I Have A Pain On The Right Upper Leg. It

I have a pain on the right upper leg. It can be on top of leg right above the knee or can start near groin on inside of leg going down to back of knee. The pain is most evident during the night. It will wake me up and the only way to stop it is to get up and walk. I had a heart cath the end of August and the Dr. went thru the groin on the inside of the right leg. It was a little sore for awhile, however, I just started having this within a month. It doesn't happen every nite. YYYY@YYYY