Confused

Casi • Recently married in Sept 2017 to the man of my dreams! Looking for a house and starting a family!! I love my nanny kids and can not wait for my own trouble makers! 💚😍
So I was suppose to get my period on Sunday. When I didn't come I deleted it on the <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period calendar</a> but now it is saying I'm due for my period on this up coming Sunday. Does it automatically change it or am I crazy?