Hi Debbie,
The sugar drink test you refer to is a Glucose tolerance test, you have a blood test and then are given Glucose to drink and then a number of blood samples are taken over the next few hours. These are tested to determine the amount of glucose in each, and shows how your body copes with Glucose(Sugar) and how long it takes to get back to normal.
The tests you have had, a fasting Glucose test gives the amount of glucose in your blood at that time of the test.
The HbA1c test gives a average glucose in your blood over the past 9 to 12 weeks, and is really the only good indication for Diabetes.
There are ranges for the results, but
Once you get the figures let us know and we can let you know what they indicate.
Always ask for a copy of your test results as they are good for reference at a later stage
Good luck