[Conveyor Belt]

Normal glucose is 70-105(110) mg/dl. I'm not sure what the units are for your reader, or how that translates out into milligrams per deciliter of blood.

My first thought is that you're taking readings too closely to consuming a meal. A fasting glucose is normally taken after fasting for 12 hours... not two hours after a meal. Two hours after a meal, your glucose may still be raised. This is why, when having bloodwork at the doctor, you're instructed to not eat or drink anything (except water) for 12 hours before the test. This is to ensure accuracy of the results.

Try a true fasting glucose in the morning after fasting for 12 hours. If you stop eating at 7pm, then you can run the test at 7am, then have breakfast. This will give you a truer sense of what your levels are.

Unless you are insulin dependent, there's really no reason to run your glucose more than once every few months, unless you're doing it for some other reason.

Also, decaf coffee still has caffine in it, and caffine will increase your insulin levels.