Glow has moved my period due date because it is late?

Hey, just wondered if someone could help me. Af was due yesterday but didn’t show so I said ‘no’ on the app and it’s moved the af due date to Sunday? Is this normal? Has anybody else had this? Should I wait until Sunday to test? Sorry for the hundred questions I’m very confused now and can’t take anymore bfn so don’t want to waste a test! Glow has normally been good at predicting if not a bit late as I’m sure last month I started a couple of days early!

Thanks xx