High WBC (white blood cell count)

Ive been going to see my Hematologist about my elevated WBC. He has done numerous test and they have all came back negative. The normal I believe is about 8-10.8.. but the first time mine was 11.8 then 11.4 then 12.8 and the recent it was a 14. I recently went to the ER for severe adominal pain and when he tested my blood it was 21. I can understand it being elevated due to me being sick w/fever but these other times I was not sick or feeling bad. Im a little worried because I hear when your WBC is high it means you are fighting an infection or it could be a cancer of some sort. I was wondering if lack of excersise, not eating right could conflict with it? I dont see why it would but just a thought. I am also diabetic which my doctor knows that so surely he would have known if it was my diabetes that was making it fluxuate.

Im not sure if any of you have had this problem or what it could be that is causing it but any information is greatly appreciated. I am still seeing my hematologist to figure out why I am just getting frustrated that he cant check a wide variety of things at one time instead of doing a few test each appointment.