Iron levels going up, but Ferritin low?

My iron levels have gone up over the year- from 11, to 33, to now 49 (norm is 40-150).

I went to a new Dr and they tested my ferritin and it was only 5. I've never had this tested before, but does anyone know why it would be so low if my iron has been going up?

Also my MCH and MCV were a little low and RDW was a little high.

Thanks