Amniotic fluid leakage?

How does one tell the difference between leaking amniotic fluid (slowly) and just being more moist in that reagion?

TMI, but today has been a particularly moist day for me, more than usual and I'm concerned about possibly leaking amniotic fluid. I put in a panty liner about 2 hours ago and it is pretty wet. It does not smell either. I cant call my doctor, because they have a weird contract with the hospital and I'd have to drive an hour to get my questions answered to go see her. I'm 31 weeks pregnant