"Are you OK with abortions in the embryonic stage before the fetal stage? Or is 50% survival rate when it becomes human? "
This is exactly why survival rate is a poor criteria for humanity.
As far as the earlier question of why implantation vs conception, it really doesn't matter. Reason being, a woman isn't ever going to know she lost a fertilized egg. It'll just pass out with her next period. How this relates to abortion: If she never knew she was pregnant, why/how would she seek an abortion. However, an implanted egg will continue to grow long enough for a woman to know she's pregnant.
This was mostly just a concession in the interest of compromise (like I said originally "I might entertain the argument of implantation vs conception") Emphasis on "might entertain".
Witty signature here...
Wii: 14 million by January I sold myself short
360: 13 million by January I sold microsoft short, but not as bad as Nintendo.
PS3: 6 million by January. If it approaches 8 mil i'll eat crow Mnn Crow is yummy.
With these results, I've determined that I suck at long term predictions, and will not long term predict anything ever again. Thus spaketh Crono.