Help On When To Retest OPK

Gisela • 💕 Expecting our second on September 2nd 💕

So I did my first OPK last month and did not get pregnant. I will be testing now in February. For when to start testing, do I go by the length of my current period or go by the length of my last test? So 29 days or 33 days? The number of my cycle varies. The shortest length of my cycle from the last 6 months has been 23 but I’m not too sure that’s correct. I need some help please 😊 I’m confused and thinking maybe I should just go see a doctor.