Implications of cycle length immediately after discontinuation of combined oral contraceptives on use of the Standard Days Method

A first post-COC cycle within the 26-32-day range did not predict a second cycle within range. Women discontinuing COC should not start using the SDM in their first or second post-COC cycle, even if the first cycle falls within the stated range. Instead, they should use a backup method until they meet the necessary eligibility criteria.