How early you can expect a BFP depends largely on how sensitive the pregnancy test is. Below are estimates of sensitivity for various peesticks. These estimates are based in manufacturer information, and can vary from test to test. Also, if a manufacturer says their sensitivity is 50 miU, that means they have to be at least that sensitive. Often tests are much more sensitive then they are advertised.
Generally, to be considered an “early” test, the test must be sensitive to 25 miU or less.
For the most up-to-date test sensitivity information, call the manufacturer of the test in question. Most tests come with an 800 number, and you’ll find the operators will either be very helpful or they will tell you that you are crazy for even asking. Either way, it’s a free call.
Sensitivity Level of Various Pregnancy Tests
Answer (Early) 25
ClearBlue Easy Digital 25
CBE Digital Weeks: 10 -156 = 1-2 weeks; 156-2600 = 2-3 weeks;
2600+ = 3+ weeks
Eckerd One Step 50
First Response Digital 18
First Response Early Result 25 (reports as low as 6)
First Response Rapid Result 50
For some “real world” peestick data, check out this chart. This data is from a pregnancy in 2009. Of course, your results may vary, but you’ll see that FRER was a surprisingly late BFP compared to other brands.