Pregnant???

Hey girls I just need some reassurance, so I've been on the pill for two months. The second month (this month) I've changed to a new brand and even when it said I didn't need a condom I waited till the 8th pill to have condomless sex. I became to worry "what if I get pregnant." Now I'm scared. I mean I shouldn't be right? I switched to my new brand properly, never missed a pill in my life. The only "flaws" I've made is last week I took my combo pill 20 mins late and when starting this new pack I changed my time from 3pm to 1pm. Then again those aren't much of flaws? Someone people ease my worrying , I'm a perfect user.