Help please, kinda new to this app.

Tracey • 28, currently ttc baby#1 with my lovely husband. Baby dust to all! God bless!
Im using the <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a> and it said that my period was supposed to had come four days ago, instead it came today. How do I update that on here? Its saying today is the last day of my period but it just started..