Is it normal for me to have my period eventhough i am on the inactive pill for my birth control. i have been taking an antibiotic for tonsillitis.

BCP ?'s: The "inactive pill" series of seven days is exactly when bleeding on oral bcp's will occur. The "inactive pills" contain no estrogen, and withdrawal bleeding will start within 2-3 days of taking the "inactive pills". Some antibiotics can interfere with estrogen absorption so if you started some antibiotics, this may cause earlier withdrawal bleeding than is customary.

About inactive pills: The inactive pills do not contain hormone medication. When a woman finishes the active pills that contain hormone medication, the next day her body has lower hormones of that type. She should have a few days of "hormone withdrawal bleeding" because she stopped taking active pills. Whether or not she takes the inactive pills, she will still bleed because she is no longer taking hormone pills.