A human embryo's brain doesn't really begin to develop until the 8th week of pregnancy
At the 10th week of development the embryo is less than 2 inches long.
A human embryo doesn't become a fetus until about the ~11th week of development
This undeveloped embryo is not a human yet, not possessing fully developed human organs, it's comparable to any other creature in it's first stages of development. Look up a picture of a sheep embryo, you will barely be able to tell the difference between that and a human embryo, because there isn't much. Our DNA is programmed to build our body in steps, the first steps of the development of life are almost the same for all animals. Where evolution made changes to us is after the first stages of development.
91% of abortions occur within the first 13 weeks of pregnancy.
Any argument for not wanting to abort a baby this early would be entirely based on the fact that this embryo will eventually develop into a human. But that would have shaky implications. Is it for some reason our moral duty to carry a baby to term that is naturally supposed to get there? Then are we supposed to have as much sex as possible too? To bring even more possible human lives to fruition? Oh shit, now we're all Mormon.
The truth is there is no fine line to cross for a bundle of cells to become a human with rights, the line is large and grey, but where ever you place the limit, it sure as hell can't be this early in the pregnancy.
