Have you ever heard of bodily autonomy? It means that everyone has the right their own body (who touches it, uses it, etc) A fetus USES a woman’s body, therefore it is that woman’s right to decide if she wants to end the pregnancy. Simple.
A ‘fetus’ does not ‘use’ his or her mother’s body, he or she is forced to SHARE her body by design.
We cannot change how we, as mammals, evolved to reproduce. All we can do is follow through with the process because it is required to protect the fundamental right to life. Being a female brings with it certain responsibilities, the first of which is to protect and nurture any child that grows inside of you.
There are at least two living people involved in a pregnancy. Each one of them are entitled to an equal right to life. One has no right to end the other’s life.
Each one has an equal right to bodily autonomy since life clearly begins at conception. When two people have equal rights, one cannot claim that their rights are greater than the other’s. They simply must co-exist.
A man and a woman have an equal right to vote. Each may cast their vote for an opposing candidate, with the net effect of rendering each other’s vote null. This did not, however, reduce either person’s equal right to vote. They simply co-existed.
If you make the choice to kill a prenatal child, you have taken their right to vote away while casting your own, upsetting the balance. They lost their right to life and their bodily autonomy, a right taken away by someone claiming to exercise their own right to bodily autonomy. One failed to co-exist with the other, thus violating the premise of bodily autonomy, which you stated everyone has the right to.