Can I go back to taking the contraceptive you took ...

Hello, I will have to take the contraceptive I took before I became pregnant because I stopped breastfeeding and the contraceptive I took during this period (norestin) may not work. Is it true that I have to wait a month to go back to taking the other contraceptive? I was taking the norestin until yesterday, can I start taking another today (cycle 21 that I used before)?