I Have Had Sex On 5th September, I Took Unwanted

i have had sex on 5th september, i took unwanted 72 within 2hours. i had my period date on 7th sep but it got delayed by 10 days & happened on 18th sep. i again had sex on 26th sep & took unwanted 72 within 1hr. but suddenly my period occurred on 5th October n lasted for 4 days but my date was on 18th. is this sign of pregnancy or side effects of contraceptive pills??