Bleeding during ovulation.

I need feedback. Guys I had sex three times this week. And took the plan b pill once. It was after the second time I had sex. It seemed that the plan b pill was stopping my normal my ovulation during this time in my cycle. Which is what I expected. But then later today I felt dizzy and faint and I went to the bathroom and saw I was bleeding dark red. It's texture is similar to menstural flow. Could I gave gotten pregnant and then "lost the embryo"? I know that is far fetched and prob impossible. Just wondering why I'm bleeding. It's not heavy bleeding but it's definitely more than spotting! Been bleeding since the afternoon.