[poodlebone]

What is your correction factor? Did you eat at the same time, or just inject the Humalog for correction? Unless you're insulin resistant, 21 units seems like a massive correction for a 257.

Whenever I get a high number and feel fine, I retest. Not too long ago I tested high and corrected, then remembered I had been cooking earlier. I washed my hands, retested and was normal. I had already corrected, though, so ended up having to eat but I did avoid the low.