Abortion.

"It's alive but it's not human."

Obviously, not live things are human.

A plant isn't human, while being very much alive.

Every living thing has a species. What species is a human fetus?

You guessed it- it's human.

It can't be anything else. 

"Fetus" isn't a species. Organisms don't change species, they stay the same species their whole lives. So if this fetus is carried to term, at birth, following your logic, it is still a fetus.

You and me, since we were fetuses, are still fetuses now (as we're the same species we were then).

Right- it's a human, like me and you. It can't be anything else. Two humans can only naturally create a human since the genetics of any other living thing aren't present in their reproduction cells.

A fetus is a living human.