Signs that the cervix is dilating include contractions that occur at regular intervals and a discharge, according to Mayo Clinic. The cervix dilates slowly during early labor, which can last up to 12 hours. Dilation becomes quicker during active labor, which can last up to eight hours.
During early labor women feel mild contractions as the cervix begins to dilate. The contractions last about 30 to 90 seconds and can occur less than five minutes apart by the end of early labor, according to Mayo Clinic. Discharge also appears during this stage. During active labor, the contractions are longer, stronger and occur more frequently as the cervix dilates to 10 centimeters.