Why not take a digital that says "pregnant" or "not pregnant"? That way you won't have to play the guessing game. I took a First Response (test 6 days before your missed period) at 11 days past ovulation and got a VERY faint positive. So, being my neurotic self, I spent more $$$ for the digital brand and got a "pregnant."
If you still get a negative with that, then you're most likely not pregnant. The next step would most likely be a doctor's visit to check hormone levels and what not.
Good luck and keep us posted!