i am a 14 year old male and have been masturbating since 12. i masturbate about twice a week.for the past 6 months or so i have been getting occasional lower back ache and sometimes in the hips, it doesn't hurt but i can feel it is there, this only seems to happen for a day or 2 after masturbation. the other day though it suddenly hurt quite a bit for about 5 minutes in the middle lower back and around the groin ( i had masturbated the day before ) is this just coincidence?? i have been to the doctor for a shoulder pain and he said that it could be i'm growing to quick. could this be the same problem or could it be something else? i am worried that it is prostate cancer??!!!!