welcome to healthcare magic ....
See if your question is weather you have prostate cancer
now ?? then the answer is "less likely " prostate cancer is usually acancer of older aged ppl , so being 15 you should not worry about your prostate.
If you are worried about your habit of feeling there is some problem with your body with everything being normal , and that this problem is really affecting your daily work and activities then you need a psychiatric opinion.
Dont worry you dont have a prostrate cancer.