OPK HELPPPPP Pleaseee

I've just started doing Opks and i only have 1 line and not 2 are these just invalid? Or is it just because I'm not there yet the app predicts another 6 days away but still only have 1 line. My periods are irregular so its alot harder for me last cycle was 34 days the one before that was 44 get hopes up too early. Any advice appreciated thanks guys baby dust to you all xxx