Kirsty, unfortunately pre-labour can go on for weeks for some people, but you will know real labour when it happens and I am sure you'll be fine. With first labours, often they are longer anyway and it's usually the second baby if anything that is born on the doorstep! So relax and remember that it's not the time between contractions, it's the length of them. If you can get 60-90 seconds long out of your contractions, then labour should be well established. So you should have good warning that all is happening - and not stopping.