"i had a blood sugar test (the finger ***** one) and my level was "perfect"."
If you had soap or alcohol residue on your finger the test results would be imperfect. If the meter was old and mishandled, uncalibrated, test strips expired the test would results would be imperfect.
The OGTT is one way to help determine blood glucose levels. Be sure to fast 8-10 hours prior. No food or colored liquids during this period. Don't cheat. Just a little bit skewers the results.