When you see red at 18 weeks of pregnancy and everything checks out fine without abdominal pain, it is not necessary to take birth control pills. Redness at 18 weeks of pregnancy can be a sign of pre-miscarriage, cervical lesions, or low placenta position. First of all, gynecological examination should be carried out to check the source of blood. If the bleeding is caused by cervical polyps, polypectomy can be carried out. If the ultrasound suggests that the placenta is in a low position, no special treatment is needed at this time, and bed rest should be provided. When the ultrasound examination and blood laboratory tests are normal, without abdominal pain, only need to follow the doctor’s instructions appropriate bed rest. However, when accompanied by paroxysmal abdominal pain, it is necessary to give progesterone and other drugs under the guidance of the doctor to protect the fetus, and follow the doctor’s instructions for regular review. When you see red at 18 weeks of pregnancy, you should go to the hospital and get timely treatment.