just like kristine said is it discolored? if it is you need to see a doctor. is it swollen. could be nerves, but could also be dvt deep vein thrombosis. probably didn't spell that right. i had the same problem kinda, and they said it could be my heart or broken blood vesils. could also be a lots of things. but if it is a different color or if it is swollen, go to the doctor better to be safe than sorry. if you don't have insurance got to the emergency room, they will have to see you. but it could also be a strain. just make sure that the bottom of your leg is not swollen or a different color.
Is your leg swollen or discolored?