After intercourse bleeding issue.

My period date was 3rd but this month i got into Periods on 9th October and i make out on 16th october without protection so i was quite unsure so i took ipill on the same day 16th october and day after that on 18th october again i makeout without protection and even on that day after intercourse i was quite unsure but i haven't took any medi because doctor here suggested not to take ipill again after a days only...so i haven't took but from today morning am.bleeding and its quite heavy flow bleeding just like periods only...and even my stomach is paining alot legs are painings am feeling weak..and today from the morning its constantly bleeding till now with quite heavy flow...am soo much worried what is happening.. please help me out..give me proper answer please...