Talk to Gynecologist on Sudden Decrease In Menstrual Flow

i had a miscarriage in January at 8 weeks. i took misopristol and then had a an ultrasound after 21 days which was clear. i had normal to heavy periods for the next 2 cycles but since past 2 months my period flow has decreased substantially from 7 days to 4 days only with very light flow. my periods have always been regular and towards the heavy side. please let me know what is the cause and treatment for this. I am so worried I hope it's not premature menopause. jazakAllah khair