So much stuff here to respond to, but..
not nearly enough time.
Oh well. I'll just respond to the OP. (and a couple of others, I guess.)
He says, "The main reason I'm pro-choice is because of the ethical issue.
I'd rather abortions be safe, legal, and rare instead of unsafe, unregulated, and done on a whim."
So, let's break it down:
"The ethical issue" is your MAIN reason; what are your other reasons?
And what is THE ethical issue? Is there only one ethical issue associated with abortion? Your statement implies (perhaps unintentionally) that there is only one ethical issue, and you are on the right side of it. It follows that those who are "pro-life" are not on the right side of "the ethical issue."
I'd be willing to wager that there are quite a few ethical issues related to abortion, and choosing a side (there are more than two) probably requires being on the right side of some ethical issues and on the wrong side of others.
So, you have simply chosen one issue with respect to abortion that you perceive is important. That's fine, just realize that you're only looking at part of the picture; a rather small part of the picture.
Also, you state that you want abortions to be safe, legal, and rare. Do you want executions to be safe, legal, and rare? How about making unwanted pregnancies safe, legal, and rare? And, wouldn't abortions no less rare if they are safe and legal, than if they are unsafe and illegal. It seems to me that if I were a women facing an unwanted pregnancy, I would be much more inclined to have an abortion if it were safe and legal, than if it were unsafe and illegal. For certain, I would be much less inclined to have an abortion "on a whim" if it were unsafe and illegal. In fact, the chances of me having me having an abortion on a whim are much greater if it is safe and legal.
I suspect what you are really saying is that you want abortions to be safe and legal, and if they happen to be rare, so much the better, but safe and legal are the most important things.
I've got enough to say about this to fill a trilogy, but suffice it to say, I view that "clump of cells" (from conception on) with its own DNA as an individual human being with the same rights as any other human being. It's right to life is no greater or less than the right to life of any other human being, including its mother. Furthermore, the right of any human being's right to LIFE supersedes another's right to liberty, and pursuit of happiness, should they conflict.
I don't profess to know for certain where life begins, but when it comes to a human being, I will always err on the side of life, just as I would hope that others would do the same for me if there were a question.
And for the smart guys (and gals) who want to talk about cells (sperm, eggs, and otherwise), leave those cells to themselves and see if they develop into a new human being. When that happens get back to me, and I'll review my position.