It’s uncommon for someone who took the abortion pill to need an aspiration procedure afterward. In fact, only 3-7% of patients required the procedure depending on which week of pregnancy they took the pill during.
Misoprostol, the second pill, dilates your cervix and detaches uterine lining. So, for those who do end up needing aspiration, this effect makes the procedure easier than it would have been without the abortion pill.