I stopped my birth control ,but now PMS and no period?

I never have unprotected sex. Ever. Even when on the pill, i still used a condom. I had to stop in the middle of the pack because I was having a rough week and skipped 3 days of pills, so I decided not to continue anymore. During that week that I skipped, I doubled up on some of the days, but also had protected (condom) sex. After stopping the pill, I bled 2 days later, but I only bled for 2 days straight. I had stopped bc pills before and knew that you had to bleed for almost an entire month getting off of them since the first time you bleed it's right after you stop, and the next time you bleed is your actual period. However....I am now a week late for my period. I wouldn't care too much about this (since before the pill my periods were never on time) if I hadn't already ovulated and am now experiencing PMS symptoms, but no period. I read somewhere that it can take months for it to come back, but i want to know if I can start taking pills again . I am terrified of being pregnant.