I once gave a negative for a WG when she messaged me 5 minutes before that she had come on
I had driven 1 hour to get there. My reasoning was she should have let me know early OR if she was due her periods, she shouldn't have agreed to the booking.
I later realised that things can change and anyone will have to cancel/change plans last minute, for many number of reasons.
Gladly, I re booked her and had a great time.