This is the same clever bait-and-switch that creationists use. No, your position is not based on biology. Who we are is a philosophical question, but in any case it requires consciousness. Are fetuses conscious? Science only knows that it takes until the third trimester (week 29+) for the brain to have developed far enough to even have the necessary capacity. It also takes until the third trimester for the fetus to be developed enough that it could survive on its own. Before that it is simply not “complete”. Science also tells us that after this, the fetus is in a very deep sleep, and during birth is animated through a high dose of an adrenaline-like hormone. That’s not faith, that’s fact.
There is still a lot we don’t know. But what we do know is that there is no unique, self-sufficient entity in existence at conception. It will become a child eventually, just like a pack of flour and chocolate will become a brownie eventually. There might be room for discussion on where exactly that is, of course. But if you really oppose abortion even for rape victims, then I don’t understand how you can honestly call yourself pro-life while opposing those unfortunate mothers’ wish to find peace.
Scientific American on Consciousness: https://www.scientificamerican.com/article/when-does-consciousness-arise/