Bleeding during ovulation?

We have been trying to conceive since sept 2010. We used preseed in Nov 2010 and had a early miscarriage. I didnt have a period all of dec. January I got my period back, and march 19 was the last day of my last cycle. I'm not sure when I ovulated or if I have. We have been using preseed again every other time we BD. When I used the bathroom I noticed pink on the toilet paper but not enough to be in my underwear. I'm just wondering if this could be implantation or bleeding from ovulation. I've never noticed bleeding during ovulation before. And I dont want to get excited thinking its implantation if its not. Any answers are helpful!! Thanks!!