Quoting Mommy of 1 1/2 :" the trick is to lay down for i think like 15 mins and then stand up (with a pad on) and if you leak ... [snip!] ... leak then its probably your water ...and if you don't feel the urge to pee when your leaking then its most likley your water"
This is what I was going to say. My YDS was born at 29 weeks due to PROM, and when it first started leaking my OB told me to put a pad on and go lay on my left side for 15 minutes and then stand up. If the pad was full or near full I had to go in to L/D. Turns out it was for me. Good luck