Reason # 2 â Implantation (Pregnancy). Pregnancy (implantation) is one of the causes of pink discharge. This is an early sign of conception. It occurs between 1-2 weeks after the egg has been fertilized by the sperm. The egg implants itself into the blood and lining of the uterine wall. Not all women experience spotting during this process. Approximately only 30% of them have a discharge. A small amount of blood makes its way through the cervix out of the vagina. It can be either light pink or dark brown.