Why am i having sudden urges to urinate more frequently than usual, but no pain when urinating?

Could be infection: Could be infection or some other irritation causing bladder spasm (microscopic blood for example). An infection could be urinary, or genital. A urinalysis will help. See your doctor or go to a clinic.

Difficult to answer: This may be a urinary tract infection or an early sign of diabetes (polyuria). Best way to eliminate either is by getting checked by your physician.