After seeing red on the expected date of labor, you will usually go into labor within 24-48 hours. Redness is caused by a small amount of bleeding due to the peeling off of the fetal membranes from the uterine wall near the cervical opening and the rupture of capillaries, and is a reliable sign of impending labor. At the time of redness, the vaginal bleeding is not heavy, but may be accompanied by mucus in the cervical canal, which is pink or dark red in color. After seeing red, the cervix usually starts to soften, the cervical canal becomes shorter and then disappears, and after regular contractions, the mouth of the uterus gradually opens up, and the fetus can be delivered naturally. Generally, the opening of the uterus will be slower before the opening of 3 centimeters, which will take about 8 hours, and after the opening of 3 centimeters, the uterus will enter the active period, and the uterus can be fully opened in about 4 hours, and the fetus can be delivered naturally in about 1-2 hours after the opening of the uterus. If the amount of vaginal bleeding is heavy, even more than the usual amount of menstruation, it may not be red, and you need to check the ultrasound immediately to exclude whether there is placenta praevia or placental abruption.