Well, with that definition, you're killing something that's going to be alive in a few weeks. And it will have a mind, and feel pain, and you're going to take that away from this thing that's developing into a PERSON. It's a person. If you have doubts about it, well, you're right. Let it grow. Might be a goldfish or a lion.
No by that definition you aren't harming something that is alive. You are assisting a naturally occurring expulsion of a clump of cells that may turn into a baby. There is no guarantee that it will, by the way. It could have a defect in it's corrupted DNA and become a cancerous lump of awful. It may become neurotic.
It's not a person. Its a clump of cells. It doesnt become a fetus or a 'person' until much much later.
It very likely will. It's not a 50/50. Isn't it a fetus right after a zygote?