Ok, Im going to take a guess here. High blood pressure, especially high blood pressure that doesn't dip overnight has been shown to cause high or "higher" blood sugar fasting numbers. Now, how is this significant to you? Well, longer term use of over the counter pain killers, especially advill have been known to cause hypertension. Im guessing that you may have been particularly sensitive to the advil and it may have caused an overnight rise in your BP which shot your fasting blood sugar up! Good news! Its only temporary. Stop the Advil and your BS should fall back into line.
This does not mean you cant take painkillers for the once in awhile pains that plague all of us. Just be aware that what happened to you on a temporary basis could be much more serious if you were to do that on a long term basis.
Anyway, its a guess at best, but it seems to fit the facts.