I heard that too high of a level of creatine raises suspicion.
This is not true. High creatinine levels are a non-issue to the labs because there are no upper limits established for creatinine. As long as the creatinine level is over 20 mg/dL, it is satisfactiory.

However, this does not mean you should go gung-ho with creatine loading. Overloading can result in long periods spent, sitting on the toilet seat.