Why get tested? To measure or monitor your estrogen levels if you are a woman who has unexplained abnormal menstrual cycles, abnormal or heavy bleeding, infertility, symptoms of menopause, or any other hormonal alterations; also used to test for fetal-placental status during early stages of pregnancy; the presence of female-like characteristics in males may require estrogen measurement as well. High Estrogen levels can also show that a reoccurence of Breast cancer may occur in women who have had it in the past. When to get tested? When your doctor thinks that you have symptoms of a hormone imbalance, abnormal vaginal bleeding, unusual and/or early sex organ development (female), or when your doctor wants to monitor the health of your placenta and fetus during pregnancy.