When should i pocket the pill?

I just get given the combined pill by my doctor and sit says on the box bear on the first day of your subsequent period, but for that could be up to 3 months (a foundation why im on it). Does anyone know why it has to be this time that you start to pilfer it They generally narrate you to start it on the first day of your extent for a few reasons:
1) ensure you aren't pregnant
2) if you start taking it at some other random point within your cycle, because you have already ovulated etc you will probably own a period mid-way through the packet, even though you are taking the pill. Most society would be annoyed because then they would capture another withdrawal bleed when they took the placebo pills/pill-free week.
3) if you nick it on the first day of your time of year, contraceptive cover is instant.

You can if you want, start taking it now (if it will be months beforehand your next period). You won't be covered for the subsequent 7 days (contraception wise) and you may get deeply of breakthrough bleeding this month, but there is no biological foundation why you shouldn't.
Start it on the next sunday.