UTI. Period time is just a hassle - it may have nothing to do with urinary burning (never normal). Usually a UTI causes burning, pain, sex pain, frequency, and urgency. You may just be catching it early and the period is coincidence. The worst case scenario would be that you have an open sore that hurts (herpes), but my money is on peeing in a cup, diagnosing uti, and taking antibiotics to cure it.