What period products do you use?
How many regular pads or tampons do you use on your heaviest day?
When your flow is at its heaviest, how often do you empty your cup/disc per day?
How many regular period panties do you go through on your heaviest day?
How many days does your typical period last?
How many days apart is your typical menstrual cycle (from the first day of one period to the first day of the next)?