just found this and hope you find it helpful
Implantation bleeding is vaginal discharge which usually contains a small amount of pinkish or brownish blood. Only about a third of pregnant women experience implantation bleeding.
When does implantation bleeding usually occur?
It can happen at the time the fertilized egg implants in the uterus, on average between 6 to 12 days past ovulation.
Should I worry about implantation bleeding occurring?
Unless accompanied by cramping, backache or increased bleeding, a small amount of blood being discharged should be considered as implantation bleeding which is nothing to be concerned about.
If this is implantation bleeding, when can I test to see if I am pregnant?
Home pregnancy tests are based on a very simple principle. They work by through the detection of the hormone Human Chorionic Gonadotropin (hCG) in a womans urine. This hormone is a hormone secreted by the developing placenta shortly after a fertilized egg has been implanted in the uterine lining.
If a woman is pregnant, the amount of Human Chorionic Gonadotropin (hCG) in her system should be around 25 mIU at 10 dpo (days past ovulation), 50 mIU at 12 dpo, 100 mIU at around two weeks dpo. Because of their high sensitivity factor ( 20 mIU/ml hCG ) in detecting human hCG, both the AimStrip pregnancy tests can confirm pregnancy as early as 6-8 days past ovulation though most women find that the test reports a positive at 9 or 10 days past ovulation.
af never comes early!! im only 6-7 dpo! its rust colored. not bright red, but not brown either. i dont normally spot before af comes because usually when i wake up in the morning its here in full swing. and ideas?? im sad. 
