ejacualtion mega probelms!!!!!! no sperm ..urine ????????? :S:S:S:S

HI ... im 15 in a few days (20th April)....Im from england...live in LOndon.....
I am not diagnossed with any diesease that i know of...
I have not had any sexual activity with anyone....
im only bout 5ft i weight bout 6.5 stone...(so im quite normal)
on hard my penis is bout.....14cm
I occasionaly wankkk every day...sometimes twice
but the size isnt botherin me its well....
I cant put it in any other way so ill tell it straight.... ::

As boys do...when i ''wank''/masterbate and the orgasam is felt...instead of the sticky semen and sperm come out...urine comes out instead.....this is very embarrising to talk about

Please help!! because at the moment i am very scared

Is it normal? .... should i seek medical advice?...does anyone else have this problem?

Please post to me...ill be very very very grateful...

thankyou...