Implantation bleeding
Since I'm on the watch for it now (I'm 6 DPO), I thought I would post some information about implantation bleeding...
Implantation bleeding occurs approximately six to twelve days after ovulation (when the ovary releases the egg). The range of time is so broad because it all depends on how quickly the egg moves down the fallopian tube and attaches to the uterus. Sometimes, it then takes time for the small amount of blood to make its way out of your body
You won't see a lot of blood if you see anything at all. Some people have such a small amount that they never notice it. Others will have enough bleeding to think they have started their period. Some women will have some bloody tissue as well.
One way to know if you are experiencing implantation bleeding and not your period is to monitor whether the bleeding is getting worse or continues. Implantation bleeding should only last a couple of days at the most. It also should be a light pink or brown color signifying that it is old blood. Of course, one of the best ways to know if you are pregnant is to take a pregnancy test the first day of your missed period.
Not everyone will have implantation bleeding. Remember, you will only bleed if a part of your uterine lining sheds when the egg implants. Don't wait around for implantation blood if you are anxiously trying to conceive because you may never have it ( courtesy of pregnancy.lovetoknow.com )