After taking an oral emergency contraception a rapid return to fertility is very likely. If you want to have sex after using emergency contraception, use a barrier method of contraception until your next period.
The hormones contained in oral emergency contraception can alter the build-up and shedding of the lining of the womb, but only for the cycle in which you take them. This means after taking emergency contraceptive pill, your next period might be on time, or earlier, or later than normal. After this your cycle normally returns to its regular pattern.
Emergency contraception pills work by delaying or inhibiting egg release. This means that the sperm that is waiting in the fallopian tube will no longer be capable of making you pregnant. If you are already pregnant emergency contraception will not interrupt your pregnancy.
Current emergency contraception is well tolerated; however like all medicines, the morning after pill can cause side effects, although not everyone gets them. If you vomit within 3 hours of taking an oral emergency contraception tablet, go back to a pharmacist and get another morning after pill to take.