Tracking peak day help

Rae

So my peak day is somewhere between the 19th and 21st (depending on the app I look at) of this month. I started tracking with OPK a few days ago, but I am not seeing the line progression that I would like. Am I doing something wrong? Should I check twice a day? Should I do it at the same time every day? I really don’t want to miss my peak days this month! TIA