Late period on BC

Hi ladies. I’m not sure why I’m freaking out but I am and need some reassurance. I have been on the pill for about 3-3 1/2 months now I’ve missed one day and doubled up the next day but that was in the very beginning. My husband and I have unprotected sex but I still have him pull out (I know I can still get pregnant). I’m confused though, I’m on my 4th brown pill tonight and I still haven’t got my period. I did take some antibiotics for a couple days earlier in the month, could that effect it? Thanks everyone. 💜💜