But if a woman is at risk of pregnancy because she was not protected at a particular time, she needs to know she can use emergency contraception. Most women should use emergency contraception only in a true emergency as a backup and not as a regular contraceptive method. Emergency contraception, also sometimes called postcoital contraception, is not as effective as consistent use of contraception and can cause unpleasant side effects. Therefore, contraception after coitus should not be used repeatedly. However, emergency contraception is generally safe and can be quite effective if used properly.
Timing is a critical factor in effective use of emergency contraception.
The copper in copper-T IUDs can prevent sperm from fertilising an egg and can also alter the endometrium, thereby inhibiting implantation of a fertilised egg. Postinor is a contraceptive pill containing a single progestin hormone, levonorgestrel, available principally in Eastern Europe. Postinor desynchronises menstrual cycle or interferes with conception processes which depends on the day of its usage. If taken seven days before ovulation date, it suppresses ovulum development. If taken after fertilisation, it prevents its implantation in uterus.