Low white count

So in some annual bloodwork I had done a couple of weeks ago, the doctor found that my white cell count is low and she wants to retest in a month. So I got on the web to see what I could find about white cell counts. Turns out, one of the primary causes can be B-12 deficiency (Pernicious Anemia). Last summer my bloodwork showed that my B-12 was on the very low end of normal, and that doctor prescribed a prescription B-12 supplement (inhaled through the nose). Because my insurance doesn't cover a lot of things, I wanted to get the Rx approved before I filled it, so I held the script and planned to call them. But instead I managed to forget and eventally lost the script and never followed up. So, I suspect that my B-12 has dipped too low and is causing the low count. However, when you're taking high doses of Folic Acid, Pernicious Anemia can be obscured in bloodwork. Not sure how they determine what reality is. Anyway, I had the doctor add a separate B-12 test to my retest lab order, so we'll see if that shows anything interesting. She also said the low count could be caused by the body fighting infection (like a cold or whatever). I'll keep you posted.