Emergency contraceptives are effective if used within 72 hrs of
1. coitus
2. ovulation
3. menstruation
4. implantation
(a) Administration of higher doses progestogens or progestogen-estrogen combinations within 72 hrs of coitus have been found to be very effective as emergency contraceptives as they could be used to avoid possible pregnancy due to rape or casual unprotected intercourse. These drugs delay/disrupt the ovulation and
fertilisation.
