OPK test

Ss

Please help! I have Been testing every day. Glow said it should have been a peak day last week. But this week I have had 1 positive test then the next day one totally negative, no line at all. Then 3 days of positives. How can this be right? 🤷🏼‍♀️ How does a girl know when to try?

Should I try a different brand of tests?

Any advise would be greatly appreciated.