Is an acorn a living organism?
What types of metabolism does an unimplanted embryo engage in? From my understanding, the really interesting stuff doesn't start happening until implantation.
The zygote (fertilized egg) undergoes cleavage again and again. After the 8-cell stage, mammalian embryo cells bind tightly to each other, forming a compact sphere of 16 cells. Then the outer layer of cells - the trophoblast - secretes water into this sphere; then, when the number of cells reaches 40 to 150, a central, fluid-filled cavity forms.
All this greowth and development involves nutrition, respiration, specialization, etc. and it allhappens before implantation.
I personally think the "interesting stuff" starts about 30 minutes before ejaculation.