Hemoglobin 13.7 low iron. Need to be concern? What's problem. Not bleeding. Anemic before w/ transfusons. Transfusions again. Iron level from the labs MCV or mvc. My hematologist was concerned. Ideas?

Iron deficiency.... It sounds like you have iron-deficiency anemia. With a hemoglobin of 13.7, it is relatively mild at this time but still needs to be diagnosed. Have you had a colonoscopy? Microscopic blood loss from the GI tract can present like this. Colon polyps or even colon cancer can result in iron deficiency anemia. These conditions are very treatable, even curable, if caught early so see a GI doctor asap!
Maybe a problem. Hard to know with just the hemoglobin value at 13.7. This is a fairly normal number for a woman at your age, so may not be a concern. However if you have been needing transfusions and you have a concerned hematologist then yes, probably there is something more going on here. The fact that you are getting transfusions means there is something potentially serious going on.