Well, blood loss and bone marrow suppression reduce total hemoglobin content. The normal range of hemoglobin is approximately 14 to 17 grams per deciliter for men. Under 10, and it's considered Anemia. Low hemoglobin counts can also be a sign of...
• anemia (various types)
• erythropoietin deficiency (from kidney disease)
• red blood cell destruction associated with transfusion reaction
• lead poisoning
• nutritional deficiencies of iron, folate, vitamin B-12, vitamin B-6
• over hydration
So be careful on how you play it with the doc. In short, I don't think you can lower your hemoglobin count. In theory, you could go and donate blood right before you see your doc, and that will temporarily lower your blood count. Worst thing...you donate blood and get to wear a special ribbon on your shirt.
And no...I don't suggest doing it.