CALL!
I have the same problem as you. With my first they had to induce with my second though I went for my 36 week appt to figure out I was in active labor, dilated to 7cm and fully effaced. All I could say was I had an uncomfortable evening the night before. No idea I was in labor. I rushed to the hospital and made it just in time. Had I not gone to the doctor there is no way I wouldn't have made it. We were out going to garage sales and I pry would have had her in the car. I didn't perceive pain till she was CROWNING! With my third I went in for early induction at 37 weeks to have an amnio. After problems with it and 8 hours of laying there they figured out I was dilated to 6 and a few hours later had my son! Again had I not gone in for the amnio that day I would have had no idea.
I've been lucky so far. I'm soooooooooooo grateful for that. Call! Sounds like you are just like me and you might be one of those ladies delivering your baby by yourself on the kitchen floor.