What day did AF start?? Help please :)

Courtney
So I'm not sure what to put for my last period. Last month I had light spotting (barely enough to need a pad) on Oct 23 and 24 and it wasn't really an actual heavy period until the 25th. This has never happened..Would I still have put it started on the 23rd?? I'm confused. This will determine if af is due today or not. Any input is appreciated!