Why Is Allylestrenol Prescribed For Irregular Menstrual Periods?

hi gud morning... i m 27yrs old... i got married 1 month before.... i had history of pco.... i have irregular menstrution , my last period april 8th... nw there s blood clots bt nt active bleeding... i saw gynecologist prescribed to take allylestrenol 5mg bd dose... cn u tell tat wat s use tat tablet fr me?