Hi I Have Really Pain In My Knee And Leg

Hi I have really pain in my knee and leg I have been told it grow pain I am 13 almost 14 they said I will stop growing for now and I don't have my Period every month it still have pain some time I cry over it I have went to the hospital for it cuz one day it was so bad they GROW PAIN. One doctor runner I got braces two year ago didn't help not at all plz help me . I have had sex in the anal and pussy it was so good can I get pregnant if I don't have my period every month. Do you recommend any positions .please help.