Do I have diabetes? I have just got 7.2 on tester?

After feeling very ill for 3 weeks (Fatigue, nausia, headaches, pins and needles in left shoulder blade) and drinking at least 2ltr's of fizzy pop a day. I thought I would try an off the shelf diabetes tester. I feel perfect some days and terrible others. I just did it and it came up with 7.2 Any ideas if this is a normal reading??