Milk flow in five months of pregnancy may be due to hormonal stimulation or considered to be due to breast cancer. 1. Hormonal stimulation: During pregnancy, estrogen, progesterone, and prolactin fluctuate in the pregnant woman’s body. When the mammary glands are stimulated by these hormones, milk will be produced and discharged from the milk ducts, which is manifested as milk flow in the fifth month of pregnancy. If you are not experiencing any other discomfort, this is normal and nothing to worry about. Keep your breasts clean and avoid infections. 2. Breast Cancer: The cause of breast cancer is not yet clear, and it may be caused by heredity, estrone and estradiol. Patients will have nipple discharge, unilateral breast discharge during pregnancy, and the nature of the liquid is plasma, watery or bloody, and some patients will mistake it for milk flow. It may be accompanied by breast lumps, breast skin abnormalities, and enlarged axillary lymph nodes. If a pregnant woman is experiencing milk flow in the fifth month of pregnancy, she should go to a regular hospital to find out the cause of the disease.