Water broke at 36 weeks?

Last night I had a gush of fluid come out of my vagina. It was definitely NOT pee.

I went to L&D since I have a lot of extra fluid so its risky and preterm labor is likely. The car ride there I saturated through a thick rag and my shorts all over my car seat. I go in the hospital and leaked all over the floor and wheelchair. I go up to L&D room and soaked 2 pads and 2 towels. The nurses were all sure it HAD to be my waters. The amniotic fluid test came back negative 2 times and all the tests for infection were negative. no explanation. I was contracting pretty regularly and dilated all the way to a 4 within 5 or so hours. So they kept me. Baby did fine all night. They Checked me again in the morning, my contractions pretty much stopped and got milder and I was still at 4cm. I asked to go home since there was no baby. I have to go back in at 12am to get a steroid shot for his lungs in case he makes his appearance. Today I've not leaked but once and it was just a small gush of fluid and have had contractions on and off very irregularly. Does this mean labor is coming?