First off, don't worry so much about scale weight. It's a basic concept, but one that bears repeating; muscle weighs more than fat. Let the mirror be your judge. If your body composition is improving, don't worry about weight gain.
Also, creatine will add weight to you. It will store more water in your cells and in your digestive tract.
Are you doing something wrong? Give it two more weeks and see. If you aren't getting stronger, seeing more muscle, and losing some fat, than yeah, you might be doing something wrong. But stick through it, and after a month of a program, if you aren't making any progress, it is time to reevaluate.