Hi. I have stopped taking birth control and I had my last period on 12/7/2012. My husband and I had sex on 12/25/2012 and when we were done I realized I was bleeding from my vagina . It was bright red and seemed more runny than a normal period. But when I checked back it was done. On the 26th I noticed very light bleeding then it stoppes again and now on the 28 it is back to bright red. What might cause this? Could it be pregnancy?