Can someone shed some light on my sugar situation?

I'm 19 with a family history of diabetes. I have had some weird problems lately where i get really shaky and irritable and p out if I don't eat something soon after it starts. My first fasting blood glucose level was 72, now it is 98. I know anything between 70 and 100 is normal, but should I be getting concerned with my levels being this close to the edge? The campus nurse is convinced I am hypoglycemic, but none of the tests have confirmed it, and it doesn't happen very often. I'm so confused because I can feel my sugar levels fluctuating, and when the dizziness starts, my levels are "normal". Does anyone have any idea what is going on? My doctor at this point is stumped, too. Any ideas about this will be extremely helpful. Thanks!