My grand daughter 17 years aged used to have periods almost after 2 months, last two months ago did not get even after 3 months so she was given Regestrone 5 mg for 5 days then she got her periods after 3 days, again now it is exceeding 2 months so she was given the same tables, can this be given every month as we don t know alternative way, being a teenager won t listen to diets suggested & no time for exercise , please advise alternative safe medicine