Why didn't my Team go though to the next round?

[Midnite]

Champions League Group Phase. I ended up Joint second with another Team. Both teams won 2, drawn 2 and lost 2. the two games against each other were drawn. My Team ended up with plus 3 goals, the other team with minus 1.
Although this would mean that my team should have qualified as Second placed for the next round, the other Team became Second, my team third. Can somebody explain this???