I started with a random pain in the back of my leg, deep in my calf. It felt like it was moving slowly up my leg, pain was bad but would calm down. Then it hit the crease of my knee...felt like I could barely bend it. now it seems to be moving back down,,,still close to the crease...and pain is getting worse and more constant. Its throbbing a lot. I was an athlete most of my life-ive had many injuries - haven't done anything to hurt myself lately-and im little worried.