Better time to use OPK?

Noemi • Mom of an only son, Dec 2015 Rainbow Boy TTC 2nd 6th Pregnancy - Due on Sep 5th 2020
Hi!
​I'm now on cd13, and have been testing since cd06. 
​Until now, only negatives, with really faint lines. 
​I've been testing around 3pm, everyday. Should I start test at night?
​My cycles are around 29 days. 
​Anything wrong? 
​Posted pic of today (cd13). 
​Thanks