Is Plan B morning after pill effective on the exact day of ovulation/conception?

We had sex with a condom and it broke and came off, the next morning approximately 10 hours later, I took both plan B pills at the same time. I had absolutely no symptoms except for extreme fatigue...extreme as in I didnt even want to move an arm. The next day I looked at my calender and realized it was the exact day that I was ovulation and conception took place. I did a little bit of research online and alot of forums have people exclaiming that the pill will not work after the egg has reached the uterus.....I took it so soon after so does that make a difference if the egg had already reached my uterus? Is it most likely that the pill worked or not? This was only a week ago.