This...
"The reason I am still wary is the evidence that the "luteal" phase of the cycle - the time from ovulation to the time the woman starts shedding her uterine lining - is shortened in some women. If the lining is shed early, I can't be sure that there could not be a loss of an embryo which is beginning to implant."
...admits the possibility that it could be an abortifascient.
See my post #6.
I'm still waiting on more evidence. (If I were a hunter, I wouldn't shoot into the woods just because I see a pair of antlers. I need to be as sure as I can be that I know what I will and what I won't hit with the bullet.)