You can take emergency contraception to prevent pregnancy after unprotected sex, or if something has gone wrong with your usual contraception method (for example a condom broke or you forgot to take your contraceptive pill).
Although there is no limit to the number of times you can take the morning after pill, you should not use emergency contraception regularly, there are much better types of contraception that are designed for regular use.
The most common type is an emergency contraceptive pill.
You can also use a copper IUD as emergency contraception. This is a t-shaped coil that goes into the womb.