Is It Possible To Have patilla tendon graph for acl reconstruction from the opposite knee?

Had A Patellar Tendon Graft Reconstruction of the ACL in my right knee November 2010. is it possible to do the same graph (Patellar Tendon Graft) from the opposite (left) knee to reconstruct my right knee if i had torn it again? I'm just curious, im 16 year old female, play rugby,softball and football. i'm five months out of surgery and my doctor dropped me from physical therapy at 3 months so i can do it at home but since then i have pain were the graph was taken from and behind my knee. any advice or information on my questions would be wonderful.Thanks