"I am convinced that Plan B does not block implantation."
And yet...
"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."
Distinction without a difference alert.
I just want more evidence, from more researchers.