First, pretty much every state in the US has banned elective abortion past the point of fetal viability, even the dark blue ones that have liberal Democratic supermajorities. That means that past 24-26 weeks--which is generally the point of fetal viability--an elective abortion is already illegal. That's six months for earliest viability. How many people do you think get up to seven months pregnant and say, "nope, changed my mind"? The answer is, almost none. The few people that get that far without wanting a baby are women that didn't realize they were pregnant because they never gained much weight, they had wildly irregular periods before pregnancy, and had spotting during pregnancy, etc. Almost all of the women that have abortions later than 13 weeks only have them because the fetus is not viable. 94% of all abortions are at 13 weeks or earlier. So right there, only 7% of abortions--which makes it at least uncommon--are even past 13 weeks, much less right up on the 24-week limit.

Anecdotally, my ex-wife had a later term (about 18-20 weeks) abortion when she was a teen. She didn't know she was pregnant because she wasn't gaining weight, and was still spotting. Her doctor told her that she had twins, that it was highly unlikely she would be able to carry to term without miscarrying, and it would be significantly detrimental to her health to try.