That isn't it.
Your doctor may decide to speed things along if a week or two has passed since your due date and your babies are still stubbornly stuck in your womb. The recommendation is that you not wait any longer than 39 weeks before delivering your baby.
Babies that linger any longer than that are at greater risk for health problems. Their food supply (the placenta) can run out, or they may have their first bowel movement (meconium) and breathe it in.