Plan B may prevent a fertilized egg from attaching to the womb (implantation).
If one believes life begins at conception, preventing a fertilized egg from attaching to the womb (implantation) terminates that life prior to that life's ability to survive outside of the womb.
Now, you can dance on the head of a pin as to whether or not the life is an embryo, a zygote, or whatever. You can dance on the head of a pin as to whether the pregnancy has started or not (and therefore if it's an abortion or not). I don't really care. What I DO know is that upon fertilization, there is an independent life that has been created. If an act is done with the goal of terminating that life, that act is morally illicit. Some would call that act murder.
If you don't believe that an independent life is created at the moment of conception, then it's a moot point. Frankly, if you don't believe that an independent life is created at the moment of conception, there's really no moral reason to be against abortion. I just have not ever gotten a satisfactory and logical answer as to when that life becomes an independent entity from somebody who doesn't believe it begins at concpetion.
Then may I assume you are against all forms of oral contraception? If so, then you have a principaled stance that you believe in and I am not attepting in any way to change your mind.
I was addressing a factually incorrect statement made in an earlier post.
As for prevention of implantation - this is one of the means of preganancy prevention provided by oral contraceptives as well as the shots, implants, etc. My point is this - if you do not have a moral issue with those forms of birth control then opposition to Plan B is groundless.
As a young woman, I believed the talk about prevention of pregnancy. I was stunned, and shed tears at the possibility that I had aborted my babies while taking this medication. I felt incredibly foolish when I learned ALL the ways BC pills rendered conception nonviable.