So I was doing some Googling.....
** Understanding How Early Result Pregnancy Tests Work **
What about early results tests, the ones that promise results three or four days before your missed period?
It’s important to know that
these tests assume a 14-day luteal phase. (That’s
the time between ovulation and when you get your period.)
If your luteal phase is usually 12 days, four days before your missed period would be 9 days after ovulation. Way too early to test.
If you have a luteal phase of 15 days, though, 4 days before your missed period is 12 days after ovulation. You still may not have enough hormone that early, but you’ve got a much better chance than someone with a shorter luteal phase.
But What About the 99% Accuracy?
If you read the instructions carefully, they are promising 99% accuracy on the day of your missed period — and not for early results. If you expect your period on Wednesday, Thursday would be the day of your missed period.
These promises of 99% accuracy, however, may not be true!
In research studies, where they compared how much hCG the test claimed to detect and how much it actually detected, the tests were only 46% to 89% accurate.
Pregnancy tests, on average, indicate a positive result only 80% of the time on day 28 of the woman’s menstrual cycle.
I guess those who don't have the "normal" 28day cycle may find this useful??
Averages of those who get a positive result :
One day past your expected period: detected 100% of pregnancies
On the day of your expected period: 96% of pregnancies detected
On the day before your expected period: 93% of pregnancies detected
Two days before your expected period: 81% of pregnancies detected
Three days before your expected period: 68% of pregnancies detected
Four days before your expected period: 42% of pregnancies detected
Five days before your expected period: 33% of pregnancies detected
Six days before your expected period: 25% of pregnancies detected