Hormone-based birth control pills prevent ovulation and can regulate a woman's period. After time, you may choose to come off your birth control, either because you want to become pregnant or no longer want to take a pill every day.Few side effects are associated with ceasing birth control, though you may experience bleeding in between periods as your body readjusts. Your period should start four to six weeks after your last pill, as your hormone levels return to normal production.PregnancyIf you stop using birth control, you are no longer protected from unwanted pregnancies. You may only have a two-week delay before ovulation begins again; once ovulation starts, you can get pregnant. Some women become pregnant almost immediately after their ovulation resumes, though it may take more time for other women. If you do not want to become pregnant, use another method of birth control like condoms.Post-Pill AmenorrheaSome women experience a condition called post-pill amenorrhea after they stop taking hormone-based birth control, where they have no periods. Post-pill amenorrhea is not serious---the birth control pill prevents your body from producing the hormones that regulate your ovulation and menstruation. It may take up to three months for your body to re-regulate to normal hormone production. If you have no period after six months and you are not pregnant, see your doctor.When to StopAs long as you are in good health, it does not matter when in your cycle you stop taking your birth control pills. If you do stop before the end of your birth control pack, expect some bleeding before your period, which can affect when your next period starts. If you choose to start taking birth control pills again, you will start with a new pack on the first Sunday of your period.