This happens to me sometimes, too. I don't eat the same breakfast every day, and I usually eat a lot of carbs (i.e., oatmeal, bagels), but there have been times when I just eat an omelet in the morning and my blood sugar rises quite a bit.

In fact, if I give the same amount of insulin for the omelet as I do for oatmeal, my blood sugar ends up higher for several hours after than if I had eaten oatmeal. Perhaps this has something to do with all the protein in the eggs - which keeps blood sugar elevated for an extended period, while simple carbs from oatmeal make blood sugars spike briefly and then drop.

We should probably ask our doctors about this, but for the time being, if you know your bg will rise after this meal, carbs or not, take insulin.