Implantation can occur from 6-12 days after ovulation, implantation is pretty rare to get (or notice). And implantation bleeding isn't really bleeding, it's spotting usually a one time pink or brown tint mixed in with CM, and a very small amount. After implantation, you should test positive on a test between 3-6 days after that, so you should be getting a positive if you were pregnant. You may have ovulated later than you thought, therefore you aren't getting a positive pregnancy test, or aren't due for your period yet, so wait another week, if still no period, take another test, if it's still negative you're most likely not pregnant. Good luck hun!!