The term “redness” refers to the appearance of bloody vaginal discharge in women after pregnancy, while menstruation is a normal physiological phenomenon in non-pregnant women, and there is an essential difference between the two: 1) Pregnancy indicator data, women with redness have a positive blood HCG or urine pregnancy test, while women with menstruation have a negative pregnancy indicator. 2) Uterus changes, women with redness will have an enlarged uterus due to the rise in estrogen and progesterone levels after pregnancy, while women with menstruation will have a normal range of uterus size. The size of the uterus of women with menstruation does not change, the size of the normal range. 3, pregnancy reactions, women who see red will have pregnancy reactions due to pregnancy, such as nausea, vomiting, drowsiness, aversion to grease, etc., while most women with menstruation usually do not have such obvious reactions, except for a small number of cases of very serious menstrual cramps, which need to be combined with medical history to further differentiate the differential diagnosis. 4, the amount of bleeding, seeing red means that the amount of bleeding is not much The minimum amount of menstruation is 20ml.