Late Period

So, my last period was 17th September and I should have my period on 16th October. I had unprotected sex on 12th October, he ejaculated outside of me and i wasnt wet because of sperm or any other liquid down there that time. Now it's 23th October and I havent had my period. The worst scenario is.. preg. But i dont want to get into that at this time. I've tried drinking 5 bottles 1000mg of vit c for the past 2 or 3 days but nothing happened. please, i just want to get my period back. what can i do? oh and i was stress too this week but for a couple of days i tried to not to be stress and calm and relax so my period could come. what can i do?