I have pain in my femur?

i have pain in my femur once every few months but yesterday and today was the worst. im 14 so i dont think its about my age. should i see a doctor. my mom says its bec i might have slept on my leg to long. but i cant move my leg without a great amount of pain. but i can walk on it but i cant bend my knee bec it starts to hurt.. wats wrong with me and should i see a doc.