Looks like the other thing you don't understand is the nature of the choice.
I think you would agree that it would be wrong to treat you the way I might treat a corpse just because, if we wait a bit, you will become a corpse.  After all, your potential status is not your current status.  When you finally die, you will cease to be a person, but you're still a person now and we can't just ignore that in the name of far-sightedness.
In the same way, an embryo's potential for personhood does not constitute personhood, and potential rights are not actual rights, so nobody is choosing life or death for a person.  When a woman chooses not to become a mother, it is the pregnancy that is aborted, not a person.  The actual rights of an actual person are being recognized as primary over the potential rights of a potential person.
Of course, if you're really against abortion, like I am, not just choice, the real solution here is to allow comprehensive sexual education and full, free access to contraception.  Women who don't have an unwanted pregnancy are never in the position to even consider an abortion.