Impending Labor?

I will be 39 weeks on Thursday. I had my strongest BH last night, and I've had a few today. Tonight, I can feel him pushing down so much than I can literally feel myself dilating more. A week ago, I was 1cm and 50% effaced. There is so much pressure that I can't walk unless I'm holding onto something or I will literally fall to the floor. And when I sit, my tailbone hurts like hellllllllll (well my whole pelvis kills me but it's super bad when I'm sitting). Also, I thought I peed myself earlier but when I checked, it was liquidy discharge. Could I be in labor??