Im an 19 year old male Ok heres the deal about 4 months ago i had unprotected sex with a girl 3 weeks after i got dishcharge and itching in my urethra so i went and got an STD test for chlamydia and gonorreha,Syphillis,hiv,herpes 1 2 3, So the results came back all negative but i still had this dishcharge and irritation so my dr gave me some bactrim the bactrim worked and it all cleared up so about a month passes and i masturbate and then it comes back again the disharge and itching so i stopped masturbating and it went away about another month passes and i masturbate again and then it recurs again same dishcharge and irritation but no burning when i pee any ideas what this might be???