Cycle has changed

Hello,

I’ve only recently started using <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a> as I’ve previously been using Flo.

I back tracked all my cycles since January and my period start date has now changed.

I was a day late today as it was meant to start yesterday apparently but now that I’ve added in my last 6 cycles it’s changed to period in 2 days

Is this normal ?

Thanks