No surprise that the misogynists apparently didn't read the linked article, which says:
The notion that morning-after pills prevent eggs from implanting stems from the Food and Drug Administration’s decision during the drug-approval process to mention that possibility on the label — despite lack of scientific proof...
Experts say implantation was likely placed on the label partly because daily birth control pills, some of which contain Plan B’s active ingredient, appear to alter the endometrium, the lining of the uterus into which fertilized eggs implant.
Altering the endometrium has not been proven to interfere with implantation.
But in any case, scientists say that unlike the accumulating doses of daily birth control pills, the one-shot dose in morning-after pills does not have time to affect the uterine lining.
Studies have not established that emergency contraceptive pills prevent fertilized eggs from implanting in the womb, leading scientists say.
Rather, the pills delay ovulation, the release of eggs from ovaries that occurs before eggs are fertilized, and some pills also thicken cervical mucus so sperm have trouble swimming.
It turns out that the politically charged debate over morning-after pills and abortion, a divisive issue in this election year, is probably rooted in outdated or incorrect scientific guesses about how the pills work.
Because they block creation of fertilized eggs, they would not meet abortion opponents’ definition of abortion-inducing drugs.
Later, in 2007, 2009 and 2010, researchers gave Plan B to women after determining with hormone tests which women had ovulated and which had not.
None who took the drug before ovulation became pregnant, underscoring how Plan B delays ovulation.
Women who had ovulated became pregnant at the same rate as if they had taken no drug at all.
In those cases, there were no difficulties with implantation...
http://www.nytimes.com/2012/06/06/h...l?pagewanted=3&google_editors_picks=true&_r=1