"Due date" is a very misleading name. Everybody knows that this is only an estimation, nevertheless everybody are still surprised if the labour starts earlier and everybody gets impatient and frustrated if the due date passes and nothing happens. It is very easy to put a given date it in the calendar and forget that it was only a rough estimation.
The thruth is that most of the healthy babies are born within two weeks of their due date. This gives you a four-week window. You can put a thick line on your calendar over those weeks, saying "birth any time now". Now remember that the preparation deadline is the beginning of the window, not the middle.
Fixing the due date may get in the way of a natural birth. The labour is most likely to start when the baby is ready and the mother feels prepared, safe and relaxed. Meanwhile, many of us decide that we still have time - it's well before the due date, so we feel neither prepared nor ready. We get nervous as the date approaches, as there are still some loose ends. Then we get confused once the due date passes and nothing happens, then we get annoyed with everybody asking where is the baby and if we plan to be pregnant forever. Finally we get more and more anxious because the doctors don't like if the baby takes more time than the statistics suggest and start to talk about induction. This is how we wasted the window: for four weeks we did not feel relaxed enough to give the baby a clear signal that it is safe to come out now.
Erase "due date" from your calendar and put a thick line with "birth any time" over those four weeks. If this helps, divide your list of things to do into two parts: less important and crucial. Have the crucial done before the window opens and leave the less important for later - so you will keep yourself moderately busy while waiting. Plan your activities for the whole four weeks, always building in cancelling option - if arranging a meeting with friends, agree that you will call each other just before setting off, to make sure you are not in labour. Once you are done with the essential preparations, you should get a green light in your head. Now, when you feel a slight contraction, instead of thinking: "Not today, I hope! I've still got some things to do!", you should feel anticipation and excitement, you should say "Maybe I'll meet my baby tonight?...".
Finally, I should precise that by saying "due date", I mean the "estimated birth date" as defined in the U.S. or U.K. Some nations, like France, like to define those differently. I have heard that in some countries the doctors believe that a pregnancy should take "nine months or so" and do not stress women with deadlines like due date and induction date. Wise move.