I am 37, 205lbs, play soccer 3x-4x a week plus run, non smoker. I have been having a throbbing pain in my calf, like dead leg. It is very painful, hurts to walk but just feels over tired. Yesterday, I decided to push my limits and walked on the treadmill for 3 miles and of course it made it worse. I had a deep knot before (6 years ago, marathon) and had to see a physical therapy but this feels different. I am also a candidate for factor 5. Can simply stretching work this out or need to see a doctor?