This spotting can be due to implantation spotting or intermenstrual spotting
. Main causes of spotting between periods
could be due to pregnancy, birth control pills, infection in an area of the body related to menstruation (including the vagina, the cervix and even the bladder). Other causes could be polycystic ovarian syndrome, diseases of pituitary gland, hormonal imbalance of estrogen and progesterone and uterine abnormalities like fibroid and cervical dysplasia.