If the bacteria were only in the epi then theres a chance a urine test would not pick it up as the epi is not connected but if you did have gono or chlamydia before, you would have had symptoms in your urethra first like a big time white penis discharge, burning while urinating or with chlamydia, urthrea itching. In my experience most all men would have urethra symptoms first and with gono i would say all men would have symptoms.