No science says life begins at conception. If you can prove agreement by all involved that a zygote, then an embryo, then feotus, is "a baby," you will have won the argument. Show that.

Meanwhile, providing contraception, and preserving the biosphere is far more pro life. Not just because it avoids abortions, but also because it recognizes as ALL agree that a life support system requires a biosphere and a balance of diversity and agency.