How do I use OPK?


Hi, I’m new. This is month 2 of TTC #3. Never had to calculate until now that I’m 35 and DH 51. I got a pack of Clearblue (10 tests). I’m usually 26ish day cycles. I’ll be on “green” days per Glow starting 3/5 this month. When do I start using the OPK sticks and what times of days and how often a day?? And when I see the smile is that when we immediately BD?