Go get acupuncture and a chiropractic adjustment :) I don't think castor oil is safe, you'd have to eat 7-9 whole pineapples, walking only helps when labor starts, prunes same thing you'd have to eat them ALL day...
Evening primrose oil might help, same with sex. But I'd still go get acupuncture and an adjustment 1st. Good luck!
Intercourse, some women don't feel like having sex but I just suggest just letting him go inside to try to open up your cervix...that's what I did and it put me to 2cm and then my doctor stripped my membranes, I had contractions afterwards, hours later a baby :) Good Luck to you though!