Occasional pain when Urinating?!

I'm 15 years old and when i urinate i sometimes have a pain from what feels like up my bum. I have had problems recently with the bottom right of my abdomen, which doctors think is just a rumbling appendix or abdominal migraine as the pain fluctuates and happens every couple of months. I am having tests because they believe i also have gilberts syndrome but want to rule out anything else. I didnt know if i could have a problem with my prostate but i don't know, i masturbate about 1 a day/every2 days. Please can i have some advice which preferably isnt go to your GP! Could over masturbating cause it?