I've taken emergency contraception four times in a year.

Emergency contraceptives contain a large amount of estrogen, there is no research shows that emergency contraceptives can only be taken three times a year, the effective contraceptive rate of emergency contraceptives is only about 80%, and if women take after ovulation is no contraceptive effect, can not be used as a conventional contraceptive method, long-term use of emergency contraceptives will increase the risk of thrombosis.