Most birth control pill packages are made up of 21 days of active pills (one color) followed by 7 days of “inactive” pills (a different color), however there are some pill packs that have less inactive pills in the last row. You will typically get your period while you are taking the inactive pills since they do not contain hormone medicine.
The inactive pills are also called “reminder pills” as they remind girls to take a pill every day. However, since some pill packages have fewer inactive pills (in the last row), it’s important to either read the package insert or ask your pharmacist or doctor which pills in your pack are active and which ones are inactive. If you choose to skip the inactive pills, be sure to start a new pill pack on time.