What Causes Heavy Menstrual Bleeding While On Meprate?

I am taking MAPRATE tablet from all most 2 months now DR advice me to take this table for max 3 months. after 3 months if i stop this tablet and i have problem in periods what i have to do. Dr is there any another way to stop this

bleeding. when the periods start huge bleeding. Dr please advice me urgently.

awaiting your good advice as soon.