3 days late

Gretchen • My husband and I are archaeologists, living in west- central Georgia.
My hubby and I have been TTC for 5-6 months now. Currently, my period is three days late (it's always predictable and never this late), but my pee stick said not pregnant. What brand of pregnancy test do yall think is the best/ most reliable? Any helpful hints? I'm trying to keep my cool, but I just want to be pregnant!