If I take the 1st tablet of Microgynon-21 after the last active tablet of Atywia, will it affect the timing of the withdrawal bleeding?

If you change your birth control pills from Atywia to Microgynon 21, you can take the 1st tablet of Microgynon the day after you finish the Atywia active tablets. There is a chance that starting to use a new drug will postpone the date of withdrawal bleeding. However, it may happen that during the first few months of using Microgynon 21 there will be irregular bleeding and spotting, which is related to the adaptation of the body to use the new preparation: https://www.gdziepolek.pl/produkty/48863/microgynon-21-tabletki-powlekane/ulotka/31262 I encourage you to read the additional materials that may be useful: https://www.gdziepolek.pl/artykuly/jak-prawidlowo-stosowac-antykoncepcje