Labor and birth are such individual experiences that it is hard to make generalizations of what "all women" will feel like. I can describe my experiences and feelings, though. Your labor might be preceded by a losing your mucus plug, diarrhea, or in some cases the bag of waters breaking. For many, contractions are the first real sign that labor has definitely started. They might start out feeling like the mild cramps many women get before they start their period. Or you might feel as if you have a really upset tummy and your bowels are working over hours. Those early twitches are just the start, though. Later on, you might feel like waves of pain are taking over your body periodically.
This might seem terrible, but after two natural births, I can honestly say that while there is pain, it is not that bad. For me, it wasn't, anyway. At this stage, you will have normally headed to a hospital and you can request pain relief if you choose to do so. The thing with contractions (which indeed feel like your uterus is dancing around in your body. Which is funny, because it is!) is that the pain tends to end completely as soon as the contraction does. If you're worried about recognizing the signs of labor so you can get to hospital in time don't. There are very, very few women who do not know they are in labor.