Diseases of the urinary tract, including kidneys, ureter, urinary bladder, urethra like calculi, inflammation, benign or malignant growths, and some other less common causes can cause hematuria which could be frank blood or blood clots. You should be investigated by a Urologist. Doctor would advise blood and urine investigations, MRI or CT scan of the urinary system, a Cystoureteroscopy for diagnosis. One the proper cause is ascertained, doctor would advise you on the appropriate management. Please do consult a Urologist at the earliest.