Ferritin Level Less, Received Treatment. Feeling Tired, Losing Hair. Have Vit D Deficiency. Tests Normal. Suggestions?

My ferritin was 7 & I was sent to a hematologist . I received 2 treatments of IV iron (the smaller doses) at the end of October 2012. In mid December, the ferritin was rechecked and it was 39. The hematologist seemed ok with that, although I m still tired and I still lose hair. My H & H is normal, as is my TSH & Free T4 (although, on the low end of normal). I have significant Vit D deficiency as well. I just had my labs drawn in the middle of January, and the ferritin had fallen to 27. I ve had a colonoscopy & endoscopy and neither was a source of bleeding. I ve also had a hysterectomy , so I m not losing any blood in those areas. Any suggestions, or should I just not worry about it?