The pill is a form of hormonal contraception that prevents an egg being released by the ovaries, makes it more difficult for sperm to move through the cervix and thins the lining of the uterus so that fertilised eggs are less likely to be accepted.
As this NHS article explains, when used correctly, the pill is over 99% effective at protecting against pregnancy. The pill should be taken daily at a consistent time, because if it becomes part of your daily routine, you are more likely to remember to take it. If you take your pill over 24 hours later than your designated time, this means you have missed a pill.
Missing One Pill
Missing pills can reduce the contraceptive protection depending on how many you have forgotten to take and when. If you start your new pack a day late, or if you miss a single pill from anywhere in the pack you won’t experience a loss of contraceptive cover. In this case you should take your missed pill as soon as possible and continue to take the rest of your packet as you usually would.
Missing Two or More Pills
Starting a pack two or more days late, or missing two or more pills anywhere in the pack may impact your contraceptive cover. Only take the last pill you have missed, leaving any previous missed pills still in the pack, and finish the rest of the pack as you usually would.
If there are 7 or more pills still left for you to take, finish them and take your placebo tablets or 7 day break. If there are fewer than 7 pills left after your missed pill, finish them and immediately start a new pack missing your break.
Testing for Sexually Transmitted Infections
If you have had unprotected sex, taking a test for Chlamydia such as those provided by https://www.checkurself.org.uk/order-a-test-kit/ is advisable, so that you can seek treatment early should the results come back positive. Being well informed on your sexual health is key to avoiding unnecessary complications and passing on a sexually transmitted infection.
If you have missed two or more pills and have had unprotected sex at any point during the previous 7 days, you might need to access emergency contraception.