Am i leaking or is it discharge?

All day I've been feeling liquid come out. I'll be laying down and I feel it and I get up and I feel it. I go and check and my panties are wet and the liquid is clear, there's no noticeable discharge. I'm also having some back pain but not constant. I'll be 37 weeks on tuesday and I have a prenatal appointment that day. Should I go get checked out? I don't know if it's a big deal or not... first time mom..