I'm not a scientist, but were you a blastocyst at one time?
Only about 10-25% of all fertilized ova are capable of survival to birth.
So?
Do they teach logic in scientist school?
No. There was one particular blastocyst that went on to develop the nervous system where I now reside, but that blastocyst was not me. *I* am rooted within the nervous system of this biological organism.
So?
Do they teach logic in scientist school?
A scientist learns to observe objectively and not insert personal bias or feelings into the observations.
Until a nervous system develops, there is no objective criterion by which I can say that a handful of cells resulting from fertilization is any different than a similar number of cells growing in a petri dish, scraped from inside the mouth, collected during a biopsy, etc. Most blastocysts do not have the ability to implant and cause pregnancy, and, frankly, I am not concerned over someone taking measures to decrease the probability of a blastocyst implanting.
Plan B works to inhibit ovulation, and to make the uterine lining less receptive to implantation. This is not what concerns me. My concern is the adverse health effects likely to result from taking a strong endocrine disruptor on a frequent basis.