OP, I am the PP with the big-head son:
I was just like you, only 100% effaced, from 38 weeks to 42 weeks. It was a long, uncomfortable month, but we tried to have a sense of humor about it and we had a ton of awesome, mind-blowing sex to try to get the contractions going.
You're only 40 weeks. Just enjoy the end of your pregnancy. Sex. Hot baths with lavender Epsom salts and a glass of wine. Naps every day. Hydrate with red raspberry leaf tea. Do tummy massages with castor oil and lavender essential oil. Drape your torso over a birthing ball and rock your hips. Go swimming. Take you kids to the playground. Tell your baby it's time to meet the family!
The numbers mean almost nothing. All you have to do is rest, hydrate, relax, and let everyone love you through the end. You are blessed with a body that knows how to birth really well! That's wonderful!