What Causes Heavy Menstrual Periods And Anemia?

Hi I want a second opinion, I constantly need to go to the toilet and have found out I have aneamia, have had it before, my periods have been getting heavier to the point I flooded last month when out in public, they gave me iron tablets and something to take when I come on..I had a scan and was told that I had a fibroid that was 4cm by 3cm...the doctor told me that it was too small to be removed he also told me I had others under my womb on my left side, he told me the other side was too dark to see when they did the scan. he wont send me for surgery and I had to ask him about my aneamia and heavy menstruating, is he right or should I go and see another doctor.