Can a urethral swab find something that a ua or a ua culture wouldnt show? er doc suggested a ngu infection being missed but cant have it done for several weeks until another referral from urology?

An entirely normal routine urinalysis, without ncreased white blood cells, is pretty good evidence against NGU. It's not perfect, and urethral swab is better to detect WBC. But if you do not have visible and obvious discharge from the penis, almost certainly you don't have NGU anyway. Urinary discomfort or bladder pain, without discharge, are rarely due to NGU or any other STD.

50-60% of NGU (nongonococcal urethritis) has been caused by Chlamydia trachomatis, Mycoplasma genitalium, and Ureaplasma. The rest are caused by Trichomonas vaginalis, Campylobacter species, and pinworm infestation. Diagnostic procedure involving urethral swab can be done at primary care doctors' office. Check with your PCP.