Using Eve

Hi, just wondering if you can advise why <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> is saying I am 3 days late? Im set for a 28 day cycle, I have chosen irregular however.. But if my last period was Wednesday 23rd/9, that would make me due today yes?
<a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> is saying I was due Monday... After getting my period for over 20years I'm now very confused at how it's being calculated, lol..