my last periods lasted from the 17th-23rd oct 2015... my periods are always regular so i was expecting it on the 17-19th nov window but i started bleeding on the 15th nov lasted till the 18th...it was a heavy enough flow to require a couple of pads/day and had clots...i am sexually active which gave me a uti during this time period for which i was prescribed antibiotics... so now m worried if i am pregnant or could it just be a scare...also m having my exams currently(another cause of stress)