6 You’re inconsistent
Missing three or more combination birth control pills (the most commonly used type, which contain both estrogen and progestin) means all bets are off until you’ve taken the pills again for seven days straight—so you need to use backup birth control during that week.
If you miss even one or two of the first pills of a pack, it also means you need seven days of backup birth control (such as condoms).
Progestin-only pills need to be taken at the same time each day, with backup contraception needed for 48 hours if you get off-schedule by more than three hours.
