Go buy a digital test my love, then you wont have to squint to see if it is actually BFN or not! Implantation may have happened a day late or something though and that would cause a lower level of HCG in your blood which might cause a negative result. FWIW my last period was 3 days late after being back to normal since it returned.

Good luck Skybie, my fingers are crossed for you!!!!