Suddenly a little bit of vaginal blood during breastfeeding may be related to infant breastfeeding, female hormone level disorders, natural childbirth and other reasons. 1. Infant breastfeeding: When the baby is breastfeeding, stimulation of the nipple may reflexively cause the uterus to contract, resulting in a small amount of endothelial stripping in the uterine cavity, resulting in a small amount of vaginal bleeding. 2. Hormonal disorders: When a woman is breastfeeding, the levels of estrogen and progesterone in her body will be disrupted, which may cause cyclic changes in the uterine lining, resulting in a small amount of vaginal bleeding due to the thinness of the uterine lining. 3. Natural childbirth: If a woman gives birth naturally, there may be a small amount of bleeding due to a small portion of the cervix that has not fully healed. If a woman is breastfeeding and suddenly has a little vaginal bleeding, don’t worry too much about it, first observe whether there are other uncomfortable symptoms, and then consult a doctor for appropriate treatment if necessary.