I'm going to take contraception, what's the right start day?

I have stopped taking contraceptives on my own for a few months and would like to go back to taking more menstruation, do I want to know if I take it again on the first day of menstruation or on the first day after menstruation?
Expert answer:

The first card should always be started on the first day of menstruation, but if you are still menstruating you can start even after the first day has passed, you should only take care in the first month. From the second carton onwards always pause for 7 days.