It depends on the type of pill you are taking.
You usually take the combination pill every day for 21 days then take a sevenday break during which time you will normally get your period (for more on this see our ‘In detail’ tab). After a week, you start taking the pill again.
If you are taking the minipill you do not take a break.
When you first start the pill (either type), if you take it between the first and fifth day of your period (days 15 of yourmenstrual cycle) you will be protected from pregnancy straight away.
You might prefer one type of pill over the other. But if you decide to swap between the two you will need to speak to a doctor first.