if they don't hurt, they are BH most likely.
labor contractions are intense. remember?
when i get them, my uterus and belly get rock hard. and sometimes they make me grunt very softly. but they don't hurt, they are just annoying and make it hard to move around.
the way my friend who is an apprentice MW described it to me... the uterus is several layers of muscle fibers. when you are in labor they work in unison. when you are having a BH, it is just one layer contracting. which is why they aren't intense.
if you are confused about what's happening, try a few ounces of wine, a bunch of water, a rest, a warm bath, a few 100 mgs of magnesium, etc... if any of these things make them go away... it's most likely BH cxs.
i think true labor contractions are hard to miss, even when the BH are constant, like in my case.