Hi, three years ago I had breast cancer. About a year after the first year, my white blood count was 8. Then a year after that it went down to 3.7, 3.9 and then back up to 5.7. About a month ago or so it was down to 4.3. When it was 3.7 and 3.9 my cancer doctor wanted to do a bone marrow biopsy to see if I have leukemia. But I have had the flu a couple of times this year so my family doctor said wait because that could cause the white blood count to go down. I also have had shingles about 6 or 7 times in my lifetime; the last time a year ago. I also have hashimoto disease. Could my white blood count be down because of my thyroid disease if it is not working correctly?