Herbs & tinctures "to regulate the menses" were advertised in Colonial newspapers. Every time I hear

[Lettuce Be]

3. There are herbs that can be used, as they bring on the menses, thus flushing the uterus

Which is basically what Mifepristone does (could be wrong). Mifepristone is used for other purposes, including after a miscarriage to ensure nothing is left behind that could cause infection.

Just research which herbs to avoid if you are pregnant and you'll know which work. My guess is this was what was used to "regulate the menses" since once pregnant there is nothing to regulate as the uterus is occupied.