What Causes Heavy Menses?

Hi, doctor. I'm 44 yrs old, 5 feet in height n weigh 61kgs. I've been prescribed norcutin 5mg (2 tabsb- twice per day) by my gynae for heavy menses. I have jst finished my dose for a month n found that my menses this month has exceeded to 11 days wth less in the begining and now quite heavy flow. I also hv a fibroid. My gynae advised me 2 take the tabs for another 5 mnths and then to stop n observe the following menses. If the heavy menses continues, he advised to do a D&C to check on the cause. Pls advise. Tq.