Pinched Nerve?

I have this thing, that constantly flares up, in the muscle area on the front of my leg, directly below and to the right of my kneecap (the top of that teardrop shaped muscle that flexes when your calf releases).

With no warning, if Im in a squatting position, with my thighs past parallel, and on the ball of my right foot, I get this shooting pain, followed by heat from my knee to my toes, and a pins and needles feeling. It just remains sore after I change my leg's position, and all that day, and night, my foot feels painful... kinda sore, with dull pain.

Since this keeps happening, probably 10-20 times a year, Im not sure what it is... pinched nerve?