Very confused...

So I have another <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period tracker</a> app on my phone, and it says I'm 4 days late, but I ovulated 2 days ago. What does this mean? Should I wait to see if my period comes? I've been tired a lot, sore breasts with bright blue veins, back aches.