I Had A Colonoscopy In 2012 And Precancerous Polyps Were

I had a colonoscopy in 2012 and precancerous polyps were found. I had another colonoscopy in 2013 and it was normal. My doctor told me to be rechecked in 3 years so I am due now. I recently had my yearly blood work done and found out that I am severely anemic with a hemoglobin of 7.6. My cholesterol is fine and my metabolic panel is normal as well. The only area of concern was my hemoglobin. Two years ago it was 12.9. I have very heavy periods with clotting and I also have uterine fibroids which I have had for 10 years so nothing has changed there. Could my heavy periods, although they are the same as it has always been, be causing this drop in my hemoglobin? Also I was on my period At the time of the blood draw.