Will I postpone my period if I start using Pinda a week before bleeding?

Slinda pills are - as you noted - a contraceptive drug, there are no indications for postponing menstruation. For this purpose, rather, other hormonal preparations available on prescription are used. Sometimes contraceptive pills are used, but two-component - skipping a break or a placebo also allows you to bypass bleeding. So did your gynecologist recommend taking Pinda to stop bleeding? From a pharmaceutical point of view, I can provide information that "the disadvantage of using Slinda is the occurrence of irregular bleeding from the genital tract when taking it" - so it is difficult to clearly answer what exactly will happen if you start taking it a week before the expected period (instead of the first day of menstruation, i.e. in a manner consistent with the leaflet). With Slinda, bleeding may also not occur at all, but this is rather observed after a longer period of use of this medicine. I enclose additional information that may be of interest: https://www.gdziepolek.pl/produkty/101505/slinda-tabletki-powlekane/apteki/w-warszawie