you dont have to run to the hospital just ring them and see what they want you to do. they will more than likly tell you to take some pain relef and if you still have pains within half hour they will want you to come in so they can hook you up to the monters and see whats happening.As thats what happened with me about 30 weeks baby was fine I went home after a hour and baby came naturally at 39 weeks but its better to know than to worry iykwim. As if it is labour then you will want them to be able to have time to stop it if they can..