My day to change the contraceptive patch should be on Tuesday, but I changed it on Sunday - what to do?

I understand that your question concerns the Evra patch? If this is the initial cycle of Evra (week one), protection against pregnancy may not be maintained. The first patch should be glued as soon as possible - then the day of changing the patch (and the "first day") changes. Additional methods of contraception (e.g. condom) should be used for the next 7 days. If intercourse occurred before the delay, the possibility of pregnancy should be taken into account. If the delay is for week 2 or 3, stop the current cycle and start a new 4-week evra patch cycle as soon as possible. A new patch should be applied immediately, which marks the day of changing the patch (and this is now the "first day"). The contraceptive effect may not be fully effective - for 7 days additional protection should be used. If you have not removed the patch in the 4th week, it should be removed as soon as possible and the next one should be glued on the usual "day of changing the patch". I encourage you to read the article: https://www.gdziepolek.pl/artykuly/jak-prawidlowo-stosowac-antykoncepcje