It's possible it could be the early stages of labor. It could also just be your body getting ready. Hard to say without being there with you.
When you're in labor there will be no doubt in your mind. A good rule of thumb is "If you have to ask 'Is this it?' then it's not or at least not fully." When you're in labor, active labor, the contractions are intense. You'll have no doubt in your mind that you are having one.
Until then, sit back and relax. You'll know for sure soon enough. If it is the beginning of labor then you might not feel the contractions for another few hours or maybe not even till tomorrow morning.
at 9:04 PM on Jun. 29, 2008