Opk question

Tiffany • Everett 💙11.20.19

So I’m pretty sure I’m ot this month as my period is due between the 26 and the 30th and I got a bfn tonight. My question is do I have a better chance next month by using an opk or is it safe to say if I bd every other day from the end of af for the month that I will cover my ovulation time?