Has anyone taken the Plan B One Step pill WHILE ovulating and had it not work?

I had sex then realized I was ovulating, so I took the Plan B pill (I'm not on BC, I'm breastfeeding) about 20 ish hours later.

But, I have read that plan B only works if taken BEFORE you ovulate, but does nothing if you've already ovulated and does not actually prevent implantation... (the package say MAY prevent implantation)

so, has anyone else taken it during Ovulation and still been pregnant??