Implantation bleeding is small spotting, rarely more than 1-2 days that can happen at the time of implantation, the attachement of the fertilized egg to the uterine wall. This usually happens 6-12 days after ovulation.Some women report spotting around the time the egg implants into the uterus. There are few data available on how often this happens. But it's likely that most women who become pregnant do not experience implantation bleeding, and many women who are not pregnant experience some spotting. So when you have spotting 6-12 days after ovulation, this could be implantation spotting or bleeding. But you cannot be sure that you are pregnant until after the pregnancy test is positive, usually about 5-7 days after implantation has happened.