Am I paranoic?

Well, I took a pill every single day but not exactly at the same hour, my bf and I had sex 3 times in this month without condom but he always cum outside me, then I started to think a lot about it and worry about being pregnant... My period should started on Saturday but it got late for one day and it was like a light flow not like always and pretty short like 3 days and normally it takes like 4 or 5 days. I have the possibility of being pregnant or just my mind, the worry and the stress freaking me out.