The difference between menstrual flow and post-pregnancy miscarriage mainly includes: 1, time, most of the menstrual flow is in accordance with the usual regular menstrual cycle, post-pregnancy miscarriage will appear the phenomenon of delayed menstruation. 2, accompanying symptoms, most women do not have obvious abnormal symptoms during the menstrual flow, or in each menstrual cycle before the menstrual flow will have a similar reaction, post-pregnancy miscarriage symptoms are manifested as a sudden appearance of 3. duration, the bleeding of menstrual flow is basically the same as the usual menstrual period, coming on time and clean on time, the bleeding caused by miscarriage after pregnancy is longer, dripping or bleeding in large amount. 4. auxiliary examination, the blood HCG caused by menstrual flow is within the normal range, miscarriage after pregnancy will cause blood HCG is elevated, and blood HCG measurement is the gold standard for determining pregnancy.