Contraception takes place BEFORE conception. Anything thereafter is the ending of the progress of a developing life.
Plan B only works when it works before conception, before fertilization.
http://www.lifeethics.org/www.lifeethics.org/2006/09/review-plan-b-how-it-works-and-doesnt.html
Studies in ovulating women who have had their tubes tied, show that Plan B works to delay ovulation and to keep the sperm from getting to the oocyte, and that there’s no measurable change in the lining of the uterus. With the single (two pill) use.
I do wonder what the woman’s cholesterol level is and what her ovaries look like. Actually, I wonder why she hasn’t become pregnant, since her body is eventually going to have “break through” ovulation.