Prometrium Help!

Jill • Married • 35 • PCOS Daughter born 23/09/2015 Daughter born 27/03/2019

Hi ladies! I have a prescription for prometrium to induce my period. I'm currently on cycle day 27 and I'm supposed to wait until cycle day 35 to start taking it. Do I really need to wait that long. I am not ovulating. I'm just getting impatient I think, haha! has anyone started it earlier than recommended?