No definately go to hospital to have a CTG. I am sure everything is fine and she is just running out of room however when you are overdue you are more at risk of placental insufficency and the baby passing meconium into the amniotic fluid so although I am sure everything is fine I would go just to make sure. Then you can rest assured she is fine. A cold drink drunken fairly quickly (like the coke) or food usually gets them going but if that is not really making much difference Id go in to be checked out.