The older emergency contraception called Prostinor has to be consumed within 3 days of unprotected intercourse for it to be effective. It involves taking 2 tablets (1 tablet each time), 12 hours apart for it to work. Some women may experience nausea and vomiting since the hormonal dose is higher than the conventional hormonal contraceptives.
If this happens, you have to return to see your gynaecologist who may need to give you another course.
The newer emergency contraception, Ella, must be taken within 5 days of unprotected intercourse and only 1 tablet needs to be consumed in this case. The risk of nausea and vomiting apply as well.
In order to prevent this, gynaecologist usually concurrently prescribe anti-vomiting medication along with emergency contraception.