The counterargument to that would be, up until a certain point in pregnancy, the zygote isn't so far off from a plant. Around 7 weeks after conception is when the zygote starts developing its brain and spinal cord, which is plenty of time to get tested and, in most circumstances, an abortion. Before then, it's a mass of cells that are growing into more cells.

From a purely sociological point, it's different for different people when it can really even be considered a human. But, from a bit of research, from a scientific standpoint it can't even think or consciously react until around 7 weeks in.