Quit torturing yourself.

Wait a few more days and then test again. Eventually SOMETHING will happen -- either a test will be positive or you'll get your period.
With my first two pregnancies I kept getting negative after negative for 5 days, but I just KNEW I was preggers. I found a walk in clinic that would do a qualitative blood test with immediate results and plunked down my $50. Positive both times.

With the third I didn't have to go that route since the pee stick was positive after only 1 negative.
Best of luck to you.