Well i have had 5 babies and all 5 have come on different times to when they were due, but the one thing for me that was common was that my labours got easier, i think because i knew what to expect and knew how to deal with my body, all my labours became shorter as well.
My first baby was over due by 2 days, my second over due by 9 days, (may have been even longer but i was induced), my third was overdue by 5 days, my 4th was born the day before her due date and my 5th was 2 weeks early.
My first labour was 10 hours, second was 5, third was 1 hour 45min, 4th was 2 hours 10min and she was born in the caul (sac) and 5th 2 hours 5min.

from what i have learnt babies come when they are ready


hth