How frustrating Katzguk!
My ds was born at 39+2. So I just assumed dd would be earlier. I had a show at 35 weeks and thought OMG! MW said that could mean I would give birth within the next couple of weeks...NOT! I think I timedmy BH contractions everynight for about 3 weeks.
Dd was then born at 39+2 also. Have you tried sex??? It triggered contractions with me at 39wks, was examined and was 2-3 cm. 2 days later and still no contractions so I dragged DH off to bed again and Hey Presto!! Dd was born about 12 hours later.