It is difficult to propose a specific method of proceeding on the basis of such a short description. Especially since you did not give the name of the antibiotic used. The full list of drugs that may weaken the effectiveness of contraception can be found in the article: https://www.gdziepolek.pl/artykuly/jakie-leki-oslabiaja-skutecznosc-antykoncepcji If you are taking the Vines contraceptive pill and you have been given an antibiotic for cystitis, it is important to inform your doctor who prescribes the antibiotic about your current contraception. Your doctor will be able to assess whether additional contraceptives are needed during antibiotic treatment to ensure contraceptive effectiveness. I encourage you to use an additional method of contraception throughout the antibiotic therapy and a few days after its completion. Through the gdziepolek.pl service you can check the availability of Vines and book it at the pharmacy of your choice: https://www.gdziepolek.pl/produkty/81748/vines-tabletki-powlekane/apteki I enclose materials that may be of interest: https://www.gdziepolek.pl/artykuly/jak-prawidlowo-stosowac-antykoncepcje https://www.gdziepolek.pl/artykuly/jakie-leki-oslabiaja-skutecznosc-antykoncepcji https://www.gdziepolek.pl/artykuly/czy-jedzenie-i-picie-obnizaja-skutecznosc-antykoncepcji