I know, I know. Ignoring a due date is easier said than done. But focusing on your estimated due date (EDD) for your entire pregnancy can set you up for a pretty disappointing home stretch before you actually birth your baby.
I'll never forget my first due date. I was unexpectedly pregnant and sat there at the doctor's office, watching a gal dial up my EDD on this nifty little wheel thing. "November 4," she said, as she noted the date on my chart. Lightheaded and misty eyed, I repeated, "November 4," and that sealed my late-fall fate of wondering and waiting and basically going out of my mind as October drew to a close that year.
As it turns out, I was lucky. I didn't have to really wait. My baby was born on November 1, which was three days "early," setting me up for extreme disappointment when my second due date came and went. My second boy was five days "late," which in hindsight, was pretty silly to get worked up over considering some mamas go way over their due dates (and who are probably laughing at me right now.)
Your best bet? Tell no one when your due date is and banish the thought of it from your mind.
Of course, there really is no such thing as a due date. There really isn't. Yes, you're due 280 days (or 40 weeks) after the first day of your last menstrual period. However, this due date is really an educated guess, and is based on average menstrual cycle length and average luteal phase, resulting in an average length of pregnancy for humans. The EDD gives your caregivers a basic goal to shoot for and will customize your care according to how far along you are. As far as delivery goes, though, there are tons of factors that can bump the actual day to either side of your EDD, and many of these cannot be predicted.
Basically, you can have your baby any time between 37 weeks and 42 week, which is the old definition of "term pregnancy." This calculation may not even be used much any more as research indicates better outcomes for babies born closer to their actual due dates and the American Congress of Obstetricians and Gynecologists hopes this will discourage unnecessary early inductions. And even within the parameters of the "ideal" pregnancy length of 39 weeks through 40 weeks, 6 days, that's basically two weeks of, "Hmm, I dunno when you'll have your baby for sure."
The first time you pick up a carton of milk that has an expiration date that is actually past your EDD may make you feel like celebrating, but as any mom can tell you, these dates are just that—guesses. Planning for maternity leave can be a real beast because you really don't know for sure when you'll have your baby (unless your doc has set a repeat C-section or a date to be induced), and don't even get me started on the phone calls from relatives begging for an update.
Your best bet? Tell no one when your due date is and banish the thought of it from your mind. Keeping a countdown of weeks that go by is normal, but try not to fixate too much on that garbage due date. Yes, it can help you keep some sanity as the weeks seem to crawl by, but it can also be a beacon of hope that turns to total crap if you pass it by, and nobody wants to look at a beacon of crap.