No, I wouldn't. I believe that the age-old scientific method of defining things by their properties is valid. Why is it okay to kill a cockroach but not a house cat? Because of the house cat's *properties* that make it a house cat -- it is a mammal with fur, four paws, etc, and (more importantly to the discussion) a sentient self-aware mind capable of love and emotion. Whereas the cockroach is probably not self-aware at all, just a machine that is built to survive and find food.
A two-week old embryo has few of the properties that describe a human being. Most crucially, if you believe that the mind & consciousness are centered in the brain, as I do, an embryo that has no brain cannot have a consciousness. You can believe it has a "soul," and the Flying Teapot principle keeps you from ever being proven wrong, but it is a religious belief. Religious beliefs should not be coded into law in a Constitutional republic where citizens may disagree. And as Robin pointed out, there are contradictions even within the paradigm of fundamentalist Christianity when it comes to the "soul is created at conception" belief. If God exists, God may in fact be super-rational and far above human beings in reasoning; however, I personally feel that people make a mistake when they assume the super-rational would directly contradict human rationality at any point. The idea that God creates souls to inhabit physical bodies & then eliminates 75% of them almost immediately, for no apparent reason, is very problematic even within a religious paradigm. I'm not saying it could never be explained away somehow, but I am saying that the burden of proof is on the anti-abortionist to *prove* God exists and to *prove* that a fertilized egg has a soul and to *prove* that there is a defensible double standard for God and human beings when it comes to eliminating embryos. To say otherwise is to say that a cockroach *may* have a soul, and therefore, we should not kill cockroaches.
The idea that the first & foremost property of humans that makes us human (and valuable) is self-aware consciousness seems to be very unpopular. Some members of this board have had a "so what?" reaction whenever I propose it, if they don't just ignore it altogether. Since consciousness is the first fundamental property that separates mammals from plants, I find it hard to fathom why this idea isn't taken more seriously. And yes, I oppose late-term abortion for the reason that a late-term fetus has a brain and therefore enjoys some level of human consciousness. However, I'm still not sure that the State is the answer to the problem. It's a whole separate debate. Lost in all this are those of us who are firmly anti-abortion but believe in only peaceful/voluntary means of curbing them.