I suppose you don't care for what scripture has to say about this?
luke 1:15
exodus 21:22-24
psalms 139:13
God's Word recognizes human beings in the womb. when a women finds out that she is pregnant, that's a human being in it's earliest stages of development.
First, these Scriptures do not make claims contrary to what I say, none of them outrightly says, "There is a human being in the womb." You, I suppose, do interpret them that way,
you interpret them to say that.
Perhaps it should be up to
you who wants to use them as some kind of evidence to point out just what that is, how do these versus say, "There is a human being in the pregnant womb." ?
On Psalm 139:13, is not all creation made by God? So acts within creation, it is an active creation, for them God would be somewhat if not totally responsible. Hence the covering in the womb,
the covering of the womb, is the womb itself and God's doing.
"... me in my mother's womb," is most interesting to be noticed, and is the way a real human being like the Psalmist can refer to his most primitive origins in a womb. The assembly there, the development, the growth, we know from there being the born person, were "of him." Whatever there was "of him" at any particular point is first of all
dependent upon there being a real he, a born person.
The short and easy answer is that his reality came from there, so it's rather natural to refer to that as him, though strictly speaking there is not "him" before birth.
The "from his mother's womb" of Luke 1:15 can be best understood as "since," once he emerged, all the time from when
even the earliest possibility of having the Holy Ghost was realized, at birth.
The way I read Exodus 21: 22-24 is that if someone strikes a woman who's fruit is thereby expelled (a miscarriage), it is a rather minor infraction the payment for which is dependent on the whim of the pregnant woman's husband.
I know others who interpret it the opposite way, even other translators who make it read the opposite, so to my mind this passage is a "wash" in the abortion arguments. I don't think anyone should bother to use it; I certainly don't think it is
persuasive as an argument against abortion. Unless and until someone comes up with ancient Hebrew documents to give details of over time how it was interpreted in practice. I rather think such documents must exist, but I don't know of any scholar who has analyzed them.
You are correct to say what's in the womb are the "earliest stages of development" of a human person, but that does not mean the person then being built exists before it is an animal, a member of the species, an actual human being.