גלולות "היום שאחרי"

What is the halacha regarding use of post coital contraception (progesterone or combination pill) within 72 hours of intercourse? Does the halacha change if the questioner is an unmarried female who will abort the baby if post coital contraception is not provided (as she has undergone an abortion in the past for a unwanted out of wedlock pregnancy)? In addition, she is not even sure that intercourse took place as she was drunk (as was the possible male partner) and they have no recollection of the events that may have occurred.