To test or not to test?

Hi yall. 
Today is CD 40, mine always run 34-35 days on the dot. No hint that AF is on her ugly way. I took a HPT on CD 37 and it was a BFN. The test I used was a blue dye, CVS brand. I have heard the blue dye tests can be faulty sometimes. Still no AF, wondering if I should go ahead and test again tomorrow with a name brand or give it some more time?