Implantation bleeding can last for a day or two in some women; others may only see a single spot of blood and others may not notice it at all, according to BabyMed. Implantation bleeding typically occurs as an early symptom of pregnancy.
When implantation occurs, it usually happens 6 to 12 days after fertilization of the woman's egg. The blood that occurs with implantation bleeding is usually scant and may look like brown or pink discharge. It doesn't look like flow from a regular menstrual period, according to BabyMed.
Implantation occurs when the fertilized egg attaches to the uterine lining. At this point, the fertilized egg is a blastocyst and has made its way via the Fallopian tubes into the uterus. In addition to brief spotting, referred to as implantation bleeding, implantation is sometimes accompanied by light cramping that is felt inside the uterus and a slight dip in body temperature.
BabyMed points out that even in the presence of implantation bleeding as a sign of early pregnancy, a positive pregnancy test is needed to confirm the pregnancy for sure.