I've heard the acupressure points work, though I can't say that I've got any proof of it personally.
However there are certainly herbs which stimulate the process, & supposedly castor oil taken internally too. You may want to find a good midwife, if you don't already know one, or even see an acupuncturist, between the two of them they will definitely get things moving along!
Start talking to the baby, as though he or she were right in front of you now, and put in the word to get a move on. You are the mom, and at this point they haven't heard of
"selective deafness" ! That will come later, when all kids learn to "tune us out", LOL.
Best wishes to you & the little one, may it be an easy delivery for you both !