My wife is eight months pregnant. I've been told to stay at home as long as possible to maximize her comfort, but I'm scared I will wait too long. A common guideline is to leave home when the contractions are five minutes apart and of sufficient intensity that your wife is needing to focus in order to work with them. Much of early labor is spent thinning out the cervix.
Active labor is consistent, persistent and intense.
True labor will only become more regular. Active dilatation occurs when contractions are intense and the interval is two to three minutes apart. The best approach is to follow your wife's instincts. After three hours, I figured I'd be dilated at least five centimeters. Even though it appeared to be too early for me, I'm glad I made the decision to go earlier, rather than later.