Hello, Sir Welcome to healthcaremagic. I can certainly understand your concern. I have worked through your query in detail. As per your symptoms, the possibility of an infection, a sexually transmitted one is very high. As the urine culture is negative for the disease causing microbes, you need not worry much. All you need to do is consider a standard urinary antibiotics like norfloxacin instead of azithromycin. This drug is a urinary antiseptic and is attained high levels in urine. This will resolve the burning sensation and the problem of minor clear discharge.A consultation with a urologist will be largely helpful. Please check with your physician if he shares my view and if can prescribe these medications to you. Post your further queries if any. Thank you