Trace of occult blood in urine

Patient: Hi, since last two months i have been having a discomfort in my bladder…i checked with my doctor who advised me to do a regular urine test which showed occult blood..the doctor thought it was a normal urinary tract infection and gave me some antibiotics to take for a week..after a week i was having the same discomfort and i was advised by my doctor to continue the treatment for one more week…my problem was still there, and i went for one more urine test which was still showing occult blood (trace instead of absent)…what does it mean ? why do i have blood in my urine ? is it something to worry about ?