What's a good opk that's not expensive

Danielle

Hi girls I'm getting sick and tired of these tests I've ran out of the pink ones. Yesterday was supposed to be my Peak day, now this app is saying another 2 days. I've always ovulated around same time heres a pic of my tests. I'm shocked plus I'm testing twice a day! I've only got these green one step opks. This is getting me so stressed.

Any ideas why the tests are so low?