My doctor found a trace of blood in my urine. what can that possibly mean? i already got tested to see if i have hiv/aids, any std's & came back neg.

Trace blood ...: The urine from patients with trace blood in urine chemstrip test should be further tested with microscopic examination to confirm if there are red blood cells. If urine is done not at period and microscopic exam shows > 3-5 rbc per high-power field, that is significant and warrants further evaluation. For detail, check with your doc or urologist timely.