It may be alive but all it really is, is a sac of cells, scientifically speaking at such an early stage it cannot be considered to be human, it just a cluster of cells, that are not developed. The argument could be made that we are also a sac of cells, but we are developed. If we were to isolate a small portion of our cells and place them on petrie dish would you call that a human being, no you wouldnt even though they are living cells, the same goes for a fertilized egg. That is all.
