OK - this is going to sound completely out there BUT are you ready?? Have you emotionally and psychologically *let go* and decided to let you body take the reins??

With my VBAC (post emerg c-section for failed vaginal breech) I was so concerned about the birthdate (she was due Christmas Day) that it wasn't until I consciously decided that any day she arrived was meant to be her birthday that anything happened. 24 hours later there was a show and the next day she was here. The pre-labour was because she was posterior and I believe I had to turn my brain (and my fears) off before she would make her entrance. The mind is a very powerful tool and birth doesn't happen if there is mummy stress. The stress hormones are just all wrong!!

Maybe try for acupuncture and ask for some mummy relaxation help as well as the baby come on out stuff. Good luck