The fact that maybe you havent matured to the point where you cum yet... I know you may think that's out of the question, but there are some really late bloomers in the world... Just wait a little longer before you ask anyone...
My boyfriend said that when he was younger when he was about to cum it felt like he would have to pee also, but he cummed instead. Maybe your not relaxing or maybe you are pushing and causing yourself to pee.
have you ever tried to have sex with someone? And do you get an erection before you try to cum?
Hmmm.. I don't know. It could be the late-maturing thing, or a muscle problem. There's a muscle that constricts the urine path into the urethra, to prevent urine from coming out during ejaculation. It might not be strong enough yet, and lets both urine and semen come out, or it prevents semen from coming out. If it worries you immensely, see a doctor. I don't think it's much of a thing to lose sleep over though.
Then you should probably see a doctor about it. When the penis swells - (when it's hard) it closes off the urethra so that no urine can travel out. If you are in fact peeing when you are "almost" cumming it seems to me there's a functional problem. In other words when you're hard your urethra cannot let urine pass through, unless there is some sort of problem or issue with you, and seeing a doctor wouldn't hurt matters.
On the other hand if it's just that it *feels like* you're going to pee, well like everyone else said here- considering that cumming goes through the same nerve network as peeing, a similar sensation is a logical conclusion.
Yes I agree with the above post. If it is actual urine there is most likely a problem. You could just be maturing later. But, if not, I dunno. Definately ask a doctor. It may be embarassing, but it would be less embarassing to see a doctor and get it fixed now than to have it happen during sex later.