The black line on your belly is the stretch mark, which is also a sign of pregnancy. In fact, everyone has a vertical line in the middle of the abdomen, but it is not easy to detect because of its light color during the non-pregnant period. After pregnancy, due to the secretion of progesterone and adrenocorticotropic hormone, the color of this line deepens and is easy to find, which is a normal physiological reaction. This condition will slowly improve after delivery and does not require special treatment. After pregnancy, pregnant women will not only have stretch marks, but also skin pigmentation in other parts of the body, such as underarm skin and perineum skin. Some pregnant women will also have stretch marks, these symptoms are normal and will usually fade away slowly after delivery. In addition, pregnant women can apply vitamin E topically to lighten the pigmentation, avoid scratching and squeezing with hands, eat more fresh fruits and vegetables, and get enough vitamin C. Also, pay attention to rest, don’t overwork, ensure enough sleep, and avoid spicy and cold food.