I seem to have a clear bubble on my penis, no idea whats going on there...

Went I aint hard, it appears to be right on the tip of my penis looking down, but when i'm hard, its a bit to the right and about 1cm down from the ned of my foreskin.

Its odd, stick theres, i've jabbed it a few times, poked it and once i've 'popped' it, a dot appeared and a bit blood came out but nothing much.

I'm 17, had since I could remember, and the earliest memory is my uncle washing me and well (think he was being pervy) he made me and my cousin wash our penis heads with soap, it stung like a health forum-remember that coz I lept out the bath and ran down the corridoor screaming.

Then a few years later, saw a doctor, which mentioned injections, but nothing happened...Aged 8-9

now i'm 17 and getting kinda worried, more so incase its something that I can spread to a girl or a guy coz i've bin having oral sex, and you know, stop it before it spreads sorta thing, any ideas?

I really don't want to approach my doctor incase its nothing, incase its harmless.

Thanks