dear user about your question i would like to tell you that these symptoms of burnining sensatin and brown urine refer to having urinary tract infection urinary tract infection may be due to viral or bacterial infection....so if you found small blisters around penis and itching it suggest viral infection of hsv2 that aquired by sexual contact you need to do urine culture as primary investigative test of bacterial infection as in this case you should have antibiotics for treatment ...althaugh you took cephalexin but it may have limited effect as you didnot complete the course or there is bacteria may resist it and urine culture and antibiotic sensitivity test will detect simply the way of treatment and selection of the approbriate antibiotic that will give best results with bacteria detected........discuss with your doctor to do urine culture and antibiotic sensitivity test as it will help alot.......you should drink alot of fluids and limit your sexual contact with others untill treatment completed........wish you healthy life