 [ Symptoms ] will my beyaz birth control pills be effective if i take it 13 days after the start of my period  i ended my period last week thursday and today is wednesday 103 [ Disease ] if efficacy is your goal    preventing an unintentional pregnancy    it would be wise to use a second form of birth control such as condoms until you complete one full packet of birth control pills have a normal period and then start the next packet even then condoms will always be an effective second level of insurance