My first child is the only one who came before 40wks, and I think it was b/c I had a UTI that my OB wouldn't treat me for. My babes all went like this:
DS1 (born in a hospital): 39w 4d, 7lbs 6oz, 16hrs of HARD labor (I was on pitocin for "failure to progress" after not dilating past 3cm for 6hrs)
DD1 (home water birth): 40w 4d, 8lbs 14oz, 10hrs of wonderful labor
DS2 (HWB): 41w 3d, 9lbs, 6hrs of easy labor
DD2 (HWB): 42w 2d, 9lbs, 2hrs of intense labor w/ a lot of back pain- when she presented, her head was turned w/ her nose to my right hip, but the rest of her came out straight
If I ever get pg again, I told my MW I pray I get to start over at 40w b/c I can't imagine going past 43w OR having a faster labor than 2hrs, my MW is 45min from me, she broke every possible speed limit to get to my last birth.
But for the most part, babies come when they're ready. I know I was very anxious w/ my 2nd pregnancy to have that baby, w/ my 3rd, I was very accepting, w/ my 4th I only became anxious the closer I got to 42w and after b/c my MW felt she should send me for a NST if I got to 43w (only b/c going that "late" wasn't normal for *me*) And I think that's what needs to be remembered, look at what's normal for YOU.