App vs OPK

I have been using this app for about a year, mainly to track my period and it has been pretty spot on. Well, now we are TTC and I didn't want to rely on the app for ovulation...so I went and bought a clearblue digital test kit. The app says I have a high chance of pregnancy today, however, the digital test said there was nothing...I obviously trust the test more than the app, but has anyone else had them be way off?

I feel like I'm ovulating...my back is killing me and CM shows the signs...

This is our first cycle TTC so I'm probably just overthinking it all..