I guess I'm begrudgingly 'pro-choice', even if ethically I am mostly 'pro-life'. I think the arguments about it being the woman's choice because it is her body are stupid and idiotic, and also dumb, as well as stupid, although I think I already said that. The life inside her womb is a human being, or at the very least a unique set of cells that will become a human being, so it is not just the woman's body anymore, and thus I don't think 'a woman's right to choose' whether to kill the human inside her is much of an argument. It should be a joint decision between both parents. The assumption should be made that the developing sentient life in the womb wishes to be born, as obviously it can't be asked, and most humans do not resent being born.
All that being said, as others have mentioned, if it is illegal people will have them done anyway, and in much less safe environments. That's part of it. Also there are many medical reasons for abortion. If a pregnancy is going to kill the mother then that really does come down to 'her choice', I think. But that's all rather thorny ethically in any case.
A lot of unplanned pregnancy and thus abortion comes about due to circumstances beyond people's controls, whether they be economically, due to education, not being raised well, etc., so ultimately a lot of abortion is something that would go away in a better-organised society. Contraception should always have a free and available option to reduce the need for abortions. Also there should be much better support for children post-birth.
Honestly from what I can tell, a lot of pro-lifers don't seem to give a shit what happens to the kid after they're born, or what conditions they're raised in. If abortion is to be banned then you'd better damn well institute some kind of support relating to that.
I think Tulsi Gabbard said her belief was that abortion should be "safe, legal and rare", and although I don't really know that much about her other political perspectives, that phrase kind of sums up a fair end-goal for my abortion beliefs.
Abortion is ending a human life, after all, but it's impossible to build a functioning society without taking on some burden of 'evil' to prevent larger degrees of suffering.
Anyway this doesn't sum up all of my thoughts on the matter, just a rough rundown of where I'm at with it right now, so take of my witterings what you will.