Opk first time user!

Tiffany

hi ladies. so it's the first cycle I have used opk and on the app it's say I'm due to ovulate tomorrow but when I take the tests they are coming up negative but not even got a faint line next to the test line it's just totally negative?? all the opks I see on here have at least a faint line do you think I have a bad batch of test strips? help please!! x