Lucien Favre's team sit fourth in the Bundesliga table after nine wins in 14 games but Kramer knows they cannot rest on their laurels if they want to remain there.
A run of five wins in a row has lifted Monchengladbach to within three points of the top three but, despite being pleased with their start, Kramer urged caution.
"I am not sure if we are above our own expectations," he said. "Obviously we were not predicting a top-four spot either, but I guess the table doesn't lie after the 14th matchday.
"We need to be careful, even though we are defending well.
"The statistics are showing that as well, but of course you need to be lucky sometimes too.
"If you consider the games in Hamburg, Nuremberg or Freiburg, where we were quite lucky to have a clean sheet."
Mochengladbach welcome Schalke on Saturday and Kramer is expecting a tough challenge from the side immediately below them in the table.
"I have seen them (Schalke) in their previous match and you have to say they have plenty of quality in attack, with (Kevin-Prince) Boateng, Julian Draxler, Jefferson Farfan, Max Meyer, Adam Szalai, that's for sure," he added.
"But also in defence they have some talented players. It will be a tight game, we will try our best to leave the pitch with a win."
