To learn more about possible side effects, I made an appointment with my OB/GYN. She said I could stop taking the pill at any time, but she advised me to wait until the last pack is gone before I did. Dr. Tanouye also agreed.You can stop or restart birth control at any time you feel comfortable. BuzzFeed reports that irregular periods can occur if you stop using birth control for a brief time. However, a period calculator can help track your cycles and eventually determine what you are doing.My doctor told me that my period patterns were irregular before I started taking the pill. If my periods become irregular again, I may have to stop taking the pill. I will also need to get tests to determine why my cycles are so irregular. My doctor advised me to keep track of my periods and monitor my symptoms, as Dr. Tanouye suggested.