"Low blood cell count"

I have been undergoing treatment for prostate cancer for the past 4 years and recently received the all clear from the Oncologist. Unfortunately following regular blood tests, my GP found that my haemoglobin count was low. I have been on Fultium-D capsules for the past few months, but there has been no change in my levels. I am scheduled for a bone marrow biopsy next week at Boston Hospital to see if there is any thing else wrong.