If you meant you have some kind of external spot where white stuff can be pinched out of the skin on the penis, possibly it is some kind of cyst. If so, a warm soak in clean soapy water could help to open the cyst and drain it.
serbia_boy, a lot depends on how old you are. If you are at or after puberty, it's normal to have white stuff come out often, that is what a wet dream is and that's what ejaculation looks like. If you think it's not semen, perhaps thinking it is some kind of discharge, possibly you have an infection (though if there is no pain I would again suggest it is the normal offshoot of sexual maturity rather than discharge or pus). Little boys get erections, but ejaculation (if I remember my health-education classes) only has semen in it after puberty. Possibly you're used to the erections but have not yet seen semen and now you are (again, I wish you had mentioned your age because I am just guessing here). If you're at or around puberty, that is probably what is going on.