How soon does your mucous plug form?

The mucous plug typically forms during the third trimester of pregnancy, usually around week 37 or 38. However, the timing can vary from woman to woman, and it is possible for the plug to form earlier or later in pregnancy. The mucous plug is a thick, sticky substance that helps to seal the cervix and protect the fetus from infection. When labor begins, the mucous plug is released, which can sometimes be accompanied by a small amount of bleeding or spotting.