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Follow your doctorâs instructions. The pills prescribed for postponement of periods should be started atleast 5-7 days before actual expected period dates. Starting them late on not in appropriate dosage might lead to breakthrough bleeding/spotting etc. Depending on the hormonal dosage contained in the pill, your doctor might choose to prescribe it to be taken once a day or in divided dosages depending on what effect is required. For further clarification and assistance, visit your treating doctor/gynecologist.
Take care.