This is an excellent article written describing how due dates can be very misleading:

The Lie of the EDD: Why Your Due Date Isn’t when You Think
How the 40 week pregnancy myth came about and why it’s totally wrong.

Just another reason to sit back and not fiddle with mother nature. It’s crazy to think that if  mama has a funky cycle she’s more likely be induced for being post-date which could result in a premature baby because the way  due dates are calculated doesn’t account for variations in women’s cycles.

When mama and baby are OK, there is no good reason to hurry things along.  Waiting for Baby to come on his/her own time (even if that time is closer to 42 weeks) gives everyone the best chance.