You will know when they come because they will come and go just time them , the first one
you have to the second. then time every one
there after this means time the beginning of one
contraction to the beginning of the next. If they are coming regularly and 10 minutes apart you are in labor. Another thing to look at would be any discharge that is not normal to what you usually have, it will be thicker in consistency, and sometimes have a bloody tinge to it.