Due on today!

Lydia • 19.. TTC for my first baby.
Hello! 
Glow says my period is due today, it got my period perfect last cycle, but other then that this app has never had my period due date correct.
My cycles are very irregular, they vary from 28 days to 43 days.
Today it is 29 days since the first day of my last period... Is it worth testing or not? X