I'm sitting in dismay. Wanting to howl over this.

I've been doing LCHF since May, and have lost about 28 lbs. Tuesday, I just had my hemoglobin checked and the doctor says I'm still in "pre-diabeties" stage at 5.7 (which is where I was a year ago)

WTF???

So what are some of the reasons I've not budged?