Plan B® works like a regular birth control pill. It prevents pregnancy mainly by stopping the release of an egg from the ovary, and may also prevent the fertilization of an egg (the uniting of sperm with the egg). Plan B® may also work by preventing it from attaching to the uterus (womb). It is important to know that Plan B® will not affect a fertilized egg already attached to the uterus; it will not affect an existing pregnancy.
The pro-life movement defines prenancy as conception. Non pro-lifers like to define pregnancy as beginning with implantation.
If you believe human life begins at the moment of conception then Plan B may result in the killing of that life. It's as simple as that.
Hey, thanks, garv, for doing the legwork (finger-work?) and posting that. There's been pelnty of confusion about the specifics of how Plan B works, so the added clarity, right from the manufacturer, is warranted and appreciated.