Blood Glucose Meters...

So I realized that the meters that check my blood sugar aren't exact, but 29 mg/dL difference from one hand to another? When I first calibrate my continuous glucose monitor I have to check my blood sugar twice in a row (once from one hand and once from the other) and the numbers have always been within 10 mg/dL. I thought maybe it was the strips so I used the control solution, but that test came back normal. 

Meanwhile, I sort of want to check again because I feel dizzy and lightheaded yet I'm not low. I just finished drinking some Vitamin water because I was low when I got home from work :( It's been about an hour and I still feel crappy...