What are contractions?
The more painless, not so rhythmical, contractions that you sometimes feel are called Braxton Hicks contractions. You can feel them early in your pregnancy and they may even increase in number and strength, but they often go away when you rest.
There are also false labour pains. How do you separate them from the real deal? False labour pains are irregular, the intensity doesn’t change, they do not get closer together and they are shorter. But they can be very painful. Try a hot bath, TENS, and/or a heated wheat bag.