Emergency hormonal contraception
There are two different types of emergency contraceptives with hormones, EllaOne and Norlevo. You can purchase either type without a prescription at the pharmacy and in selected shops. These should be taken as soon as possible after unprotected sexual intercourse to ensure the best effect. Their effect is to delay ovulation, but they are ineffective if ovulation already occurred before taking the pills. You should therefore always take a pregnancy test three weeks after using emergency contraception. Some will experience side effects such as nausea, abdominal pain and bleeding.

EllaOne 
May be effective up to five days (120 hours) after unprotected sexual intercourse, but it should be taken as soon as possible. You must wait five days before starting another type of hormonal contraceptive, as the hormones may disrupt the effect of EllaOne.

Norlevo 
May be effective up to three days (72 hours) after unprotected sexual intercourse, but it should be taken as soon as possible. You can use another form of hormonal contraceptive even if you have taken Norlevo. This can be used several times during a menstruation cycle.

Copper IUD as emergency contraception
A copper IUD is the safest form of emergency contraception. It can be inserted up to five days after unprotected sexual intercourse and prevents pregnancy in 99 percent of cases. A copper IUD does not delay ovulation, but instead prevents a fertilised egg from attaching to the uterine wall.

Source: Sex og samfunn