Bodily autonomy is probably a weak argument, because it assumes that the fetus isn't a living human being deserving of the same protections against slaughter that you and I enjoy.
If it is, bodily autonomy doesn't justify murder.
If it's not, then protecting it from abortion is absurd.
In neither case though, is bodily autonomy a compelling argument.
You seem to be saying that "personhood" should be the deciding factor of abortion rights, but "personhood" is never going to be resolved to everyone's satisfaction. Bodily autonomy can and should be.
Bodily autonomy is usually clear in most instances, but it might be overridden by personhood, so it doesn’t help resolve the debate to everybody’s satisfaction.
We all just want to go about our lives within being forced by law to sacrifice our rights to our bodies.
My thing with the hypothetical kid needing a kidney wasn't that a parent refusing to donate would be a good person, it was that by principle of law it would be immoral to force them to do it. That was taking the "pro-life" perspective all the way to "it's a whole-ass person" and showing that the concept of bodily autonomy still protects the parent, even if you don't agree with what they do. I don't mind if you think I'm a monster for getting an abortion, I just want to ensure that that choice is there for those who want or need it.
I get that it's a really intense issue for a lot of people, but all I wish is that folks didn't feel like whether someone else carries their pregnancy to term is a criticism of what they've done or want to do. It's truly not. I know for myself I have a list a mile long of reasons I would never carry or raise a child; some are personal and some aren't, but I am still happy when my loved ones welcome a new member into their family.