So I started running about 3 weeks ago, added it to the sprints I was already doing to get ready for football. All going good, was easing into it so not to injure myself but I have this weird pain about 2 inches under my knee and it *feels* like a shin splint..but way too high to be one obviously. It only hurts for about 4-5 hours after I'm done whatever Im doing physically that day, be it weights, sprints, running ect, and it only hurts when I fully extend the leg, any ideas?