Sometime around the end of week three, you will officially miss your period, if you’re the sort of gal who pays attention to that sort of thing. (I know before I ever entering the trying-to-conceive game I was definitely the type who could not remember my LMP for the life of me.) And if you’re the sort of gal who enjoys peeing on your dollars, you will probably run right out and buy some of those “test FIVE DAYS before you miss your period!” pregnancy tests.
Ignore what the tests say on the box: very very very very few women will get a positive result a day before they miss a period, let alone FIVE DAYS before they miss it. I’m sure it happens, although I must admit that it has never happened to a single pregnant woman I’ve known. And I’ve known a lot of pregnant women. We all reported clear-cut positive results about a day to five days after we missed our periods, but a lot of negatives before.
For my current pregnancy, I tested on day 28 in the midst of terrible, terrible nausea but got a negative. (My cycle is about 30 days, usually.) This negative convinced me that I had the stomach flu instead of the knocked-up flu, and only after six more days of heartburn and nausea did I finally break down and buy more sticks. And boom! A resounding positive result in about five seconds.
The point is: if you MUST test early, re-test once you really and truly have missed your period.