How Long Labor Take Having Dilation And Effacing At 2cm And 50%?

Hi I m 40wks and 2d pregnant. I ve been in pre-labor since at least 37wks - increase in braxton hicks, a mucous plug fell out and a week later another one fell out, which was 2 weeks ago and lately i ve had a lot of mucous discharge that is turning more watery - i had my fluid checked on Tuesday and it was 9, increased swelling - BP 100/60 on Tuesday, increased facial swelling, diarrhea past 3 days, nausea and dry heaving last 2 days, decrease in appetite, I ve been dilating and effacing for the past 4 weeks and was checked 2 weeks ago at 2-2.5 cm and 50%, also she said she can feel the baby s head, increasing pelvic pain, mild menstrual type cramps, mild back pain, my weight has stayed the same for 2 wks and now my face is breaking out... please tell me labor is coming soon, as in tonight!