I just got back from Europe and the next day I got this pain behind my thigh. It starts behind my knee on the left where there is cartilage I think, and then goes up diagonally to the mid of my thigh. It comes every 15 min and is very painful. First day was very bad, no anti-inflammatory, or cold compress or anything helped it at all. It was just throbbing pain, and you could actually see that part pulsing with your eye while there was pain. Then it disappeared for a day, and now I have had it c