Went for a check up and had blood in my urine. went to a urologist did a kidney sonogram and blood work. everything came back fine. is there anything else i need to check? should i be worried about the blood in the urine?

I assume you have true microscopic hematuria which means there are more than 3 red blood cells/hpf by microscopic exam, not only positive occult blood by dipstick test. Urine protein/creatinine or preferably urine microalbumin/creatinine should be done. If the result reveals proteinuria or albuminuria, either micro or macroalbuminuria, you need to see a nephrologist for further evaluation.