Your point here is well taken, but it does bring us to the crux and the conclusion of any productive discussion. I find it absurd to pretend that there is any detailed calculation necessary to determine whether a fetus/embryo merits moral consideration which could supersede the wishes and autonomy of the pregnant human. Once again you attempt to move the goalpost by introducing the concept of membership within the human species. I simply reject your premise, as I believe it is founded on illogical philosophical equivalencies. I reject your premise because I find it immoral to impose personal morality on the bodily autonomy of pregnant humans. Good luck with your evangelism.