https://www.healthline.com/health/birth-control/how-long-does-birth-control-take-to-work This article says that if you start on the first day of your period, you are protected right away. But if you don't, it takes a full 7 days of the pill to then protect you. It's your count as to what day you started it, if it was past 7 days, you're good.
This is the first time you've been on a packet of pills, or you just began them again after a period?