Birth control help!!

So I just got put on a low dosage combination pill and it has 24 combination pills, 2 estrogen only pills, and 2 placebo pills. I had sex with my boyfriend throughout the month and I never got my period so I'm kind of freaking out. Is this normal? Also my boobs have gotten bigger and they're pretty sore but that can be from the pill OR pregnancy 😱😱😱 advice please!!