To determine whether a patient’s vaginal bleeding is menstrual, or a miscarriage, there are three main ways to look at it: First, observe how much vaginal bleeding is present and how long it lasts. A normal period bleeds as much as a past period and clears on time. In miscarriage, the patient bleeds less and for a longer period of time. The exception is biochemical pregnancy, where the amount of vaginal bleeding is like a menstrual period. Second, observe the clinical symptoms of the patient. The patient has high estrogen and HCG levels after pregnancy, and the patient mostly has nausea, vomiting and other early pregnancy reactions, and usually no menstruation. Thirdly, observe the patient’s blood and urine HCG, which is also the final criterion to determine whether it is menstruation or miscarriage. If the test is positive for urine HCG, the blood HCG level is elevated, and then bleeding and exclusion of ectopic pregnancy should be considered as miscarriage.