When to start testing?

Madeline • Tue, Nov 21 • Mom to Landry, wife to Brad and fur mom to Griffin and Baylor!

Okay y'all, second month TTC because AF decided to make her unwanted appearance today 😭 Anyways, I know last month I ovulated either CD 17-18. I have pretty irregular cycles and was wondering when I should start using OPKs this month just to be careful and not miss it! Any suggestions?