Sugar will only spill over into urine when blood sugar is very high, so the negative here does not exclude diabetes.
Given your readings, a diabetes spectrum (impaired glucose tolerance or type 2) disorder seems plausible enough - from your use of "most of the time" i assume that you get readings > 7.8 occasionally, which would suggest IGT; however, diagnostic criteria are in terms of OGTT results so it's a bit difficult to interpret without knowing what, and how much, you eat.
The 11.2 mmol/l reading points to T2 as one or two random BG tests > 11.1 are sufficient to diagnose diabetes.