"Oh, halfway!" said a friend yesterday, when I told her I would be twenty weeks along today. I said, "No, I'm not halfway." (I was a little cranky because she had just commented on big I was. She was thinking I was earlier in the pregnancy.)
Twenty weeks isn't the halfway point of an average pregnancy, because for the first two weeks of a standard forty-week pregnancy you're not pregnant. On average, a woman is halfway through gestating at 21 weeks.
I, however, am...above average. (Note the positive spin I am attempting to give this, like focusing on the "advanced" in "advanced maternal age.") My boys have all been late: 6 days (Alex and Marty), 10 days (Joe, and I started telling people who commented on my belly that it was actually my pet watermelon, because late pregnancy messes with my head in a big way and I cannot handle questions like "Didn't you have that baby yet?"), and 8 days (Pete). Mean length of gestation: 273.5 days. I haven't told anybody my actual due date since I was pregnant with Alex, and this time around I just say, "I'm expecting the baby to arrive between Christmas and New Year's."
I'll be halfway in 10.75 more days (she said pedantically).