hello first i would like to inform u that when to take emergency contraceptive
if u had menstrual blood on 22feb and u had sex on 28th feb than u doesnt require any kind of contraceptive to prevent pregnancy
because if any female having normal cycle and regular at interval of 28 days that means her ovulation is on day of 14 th from 1st day of menstrual bleeding and that ovum survive for 48-72 hrs and during this phase / time sperm comes in contact than and than pregnancy remain so here if ur menstrual h/o is regular so there is no chance of ovulation on 6 th day of ur periods u took emergency contraceptive on wrong time
and one thing always remember emergency contraceptive pills r also a hormonal
preparation so if once they goes into ur body there drastic changes occur in ur hormonal level and that pills induce bleeding so now dont took any medicine and wait for next menstrual bleeding and if u have regular sex than took contraceptive pill regularly like pills CHOICE for 3 month it will also help to regulise ur menses.