That's total bullpuckey. While it's certain there were some illegal abortions going on pre-Roe, the left has made a long career out of mythical claims of millions of back alley abortions and death by coathanger. It's propoganda, and you've bought it hook line and sinker.
SOME illegal abortions? How do you know there were only "some"? There were no statistics kept. Ask anyone who was a teenager or adult pre-Roe, and you will find that almost all of them knew "some" who had illegal abortions.
And if you use common sense, you will be able to figure out that very few change their behavior just because it's illegal. Do you ever drive above the speed limit? That's illegal. Did you ever drink alcohol before you were 21 (or do you drink it, if you're not yet 21)? That's illegal. Etc.