My boyfriend and I were making out and he ejaculated outside me

hi, my boyfriend and i were making out and he ejaculated outside me, just to be safe i had an ipill 2 hours after it. this happened on the 22nd september and i had withdrawal bleeding on 26th september, which lasted 5 days. i had my last period on 12th september and my periods were due on 10th october but i am 6 days late now. last week i experienced abdominal pain, acne and body aches, usual signs of my periods going to begin but i still haven't got my periods. should I be worried? when will my periods start? should i count my date from the date of the withdrawal bleeding? I am worried, please help.