No LH Surge!!

I have yet to have a positive opk! I realize there could be many reasons why I'm not getting it (not testing at the correct time, etc), but I'm wondering if I should keep logging it? Each day I log no surge, it bumps my fertile window back a day. AF due August 6th, and Glow currently says my fertility peak is July 30th. Help! should I delete the data or leave it? When I log my next period (which I'm assuming is coming ?) will it automatically correct my fertile window? Thanks for your advice!!