Could you tell me what is the reason for waiting 7 days after a missed birth control pill?

Do you?: In general, if you miss 1 pill, you take it as soon as you remember and then take the next at the usual time. This may mean you take two pills at once. If you do this, you don't have to wait 7 days. If you miss more than 1 pill, you still don't have to wait but you do need to use condoms or other back-up method. Each pill comes with an insert that tells you what to do if you miss pills.