These are called Braxton Hicks contractions or false labor, and they usually begin several weeks before delivery. Although these changes in the cervix cannot be detected except by medical examination, when this happens a woman will usually have an increase in mucus discharge from the vagina, which is clear, pink, or slightly bloody. This may occur several hours before or during labor. This happens when the linings of the sacs around the baby tear and the membranes rupture, which is commonly referred to as the breaking of the bag of waters. This gush of liquid is uncontrollable.
Rupture of membranes can happen several hours before labor begins, or any time during labor.
Sometimes the doctor punctures the membranes if they have not broken after labor begins. While these are clear warning symptoms that labor is about to begin, they are not precise in predicting when birth will occur. This is because every pregnancy is different, even for one woman. However, if any of these symptoms happen before the 37th week of pregnancy, the woman should call her doctor right away. Otherwise, a general rule of thumb is that a doctor should be called when labor pains become regular and can be timed, and when they are accompanied or preceded by any of the other warning symptoms of labor, or when the bag of waters breaks.