If you were to ask most people if an 13-year-old girl should be forced to give birth to a baby after being impregnated by her own father, I think they would say no.
If you were to ask most people if a woman should have to risk her own life while going through labor, I think they would say no.
If you were to ask most people if they believe abortions should be safely performed under a doctor’s care, I think they would say yes.
But for some reason, a lot of people don't like to identify as being pro-choice. There seems to be no better explanation for why other than people, who oppose safe, legal abortions, have done a fantastic job stigmatizing the word. Even if people who identify as “pro-life” are in the minority, they are a noisy bunch. “Pro-aborts” and “baby killers” are commonly used words. This stigma works much the same way that few people nowadays would say women shouldn't drive or be paid equally to men — and yet tons of people are still reluctant to say “I’m a feminist" for fear of being labelled a "feminazi".
Anti-abortion folks have also polarized the conversation so that it is just about abortion. The reality is that an abortion after six weeks is totally different from an abortion after eight months, yet there’s no leeway given. If you’re a baby killer, you’re a baby killer.
It really matters for people to have ownership, so to speak, about what they mean. I proudly call myself pro-choice; I just personally explain my beliefs in more detail, “I believe abortions should be safe, legal and hopefully rare.” If pressed for why I think so, then I will say, “History has shown women have always terminated pregnancies somehow. It’s better for women themselves and for their families if these abortions are legal and therefore safe.” It’s a more nuanced explanation that reflects my values and it also happens to be the explanation that is most true for me.