I think it is rare that contractions come on right away and you start going in labor. You tend to start showing other little signs that lead up to the contractions. A lot of people start with the baby droppping. You may not notice it yourself....but don't be surprised if someone else comes up to you a says "Oh my, you have dropped!" Some people start to lose their mucosal plug. That is a sign that your cervics is getting ready. You may get a "bloody show," which is that mucus and it tends to have bright red blood streaked in it. You may have more braxton-hicks contractions....they are not painful, just a tightening of your belly....preping you for the real ones. You may also get a big burst of energy.....it's a hormone release that is also a sign you are getting ready. Your water breaking is usually a no brainer and after that, most people will start with contraction. Not everyone is the same but contractions usually start coming on slow and then increase with time and intensity. When you are having them, you will know. Good luck. I hope some of this was helpful.