Two different period apps?

Chelsea • 21 y/o 🤘🏾 1 miscarriage 💔👶🏾 ttc 4ys

So I use two different <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period apps</a>, the first one I use is the most accurate to my period but not when I ovulate but glow is more accurate when I’m ovulating. My first app says my period is in 6 days but glow says 10 days. Anybody else?