<prompt> The progestogenic emergency contraceptive pills act by -Altered cervical secretionInhibition of ovulationAnti-implantation effectInhibition of LH secretion  <response>: Ans. is c i.e., Anti-implantation effect o If ovulation and feilization occur, the blastocyte fails to implant anti-implantation effect because endometrium is either hyperproliferativer or hypersecretory; not suitable for nidation. o This is the mechanism of action of postcoital emergency contraceptive pills. 