Hi dear, sorry to learn about that. If your menstrual flow suddenly reduce but remained regular, then you probably have an obstruction to the outflow of your menses caused by an injury to the inner lining of your womb, i.e. the endometrium, or to the passage within your cervix, i.e. the cervical canal, or rarely to the inner lining of your vagina. When such injuries heal, they form scar tissues that obstruct or block the normal flow of your menses. Possible causes include past history of multiple D and Cs or a D and C complicated with infection, a uterine surgery like myomectomy, a cervical surgery like cone biopsy, and rarely insertion of corrosive agents into the vagina. Before deciding on an appropriate treatment, a detailed assessment needs to be done by a specialist. For more information, kindly read up all the articles on reduced menstrual flow starting with REDUCED MENSTRUAL FLOW: INTRODUCTION AND CAUSES or CHAT WITH OUR CONSULTANTS.