Can someone help please? my urine test for diabetes was postive. but the blood test was negative. what does that mean?

That means you had: Sugar in urine i'll assume 'blood test' was a simple glucose test, not hga1c etc rarely its due to a genetic defect-kidney can't reabsorb sugar filtered into urine. Not dangerous , normal life span. More likely is blood sugar represents 1 second in time, but glucose in urine represents sugar that was high enough to spill into urine any time since last urination- - you may have diabetes-see md.