As long as you take your birth control pills regularly, there is little risk of pregnancy if you have unprotected sex while taking the inactive pills in your birth control pack. Some birth control pills package seven white pills to be taken between packs. These pills contain no hormones of any kind. This is the seven-day window when your menstrual period should occur.
Though risk of pregnancy while taking birth control pills is less than 1% (when taken regularly and as prescribed), some doctors estimate the risk at about 8% due to missed pills and irregular pill schedules. If you feel uncomfortable having unprotected sex between pill packs, there is no reason you can’t use a backup method of birth control.