Could antibiotics delay your period if you are on the birth control pill?

Yes: Yes, but more importantly, they can INTERFERE with the EFFECTIVENESS of the contraceptive effect of your pill. Whenever I prescrive antibiotics for my female patients on the pilll, I counsel them to use a barrier method (condom) for contraceptiive purposes. For how long depends on how long you are on the antibiotic and where you are in your pill pack. Delived quite a few babies from this.