Don't fixate on the scale! Our weight is not an absolute number but a moving target, so it's the trend that matters. The scales may be calibrated differently. When I weigh in at home, I do so without clothes and just accounting for those at the doc's office can add several pounds. You may also have weighed in at a different time of day than you normally would at home. Since you tend to be your lightest in the morning and see an increase throughout the day (as you consume food and water), this will have a big impact, too. If you are using the scale to judge your progress, use the same scale at the same time of day wearing the same clothes (or lack there-of) to get the most reliable results.
The important thing is that your clothes are fitting better- this is absolute proof that you're doing something right! Scales are such a bad measure of weight loss for so many reasons and you'll drive yourself crazy if you refuse to see real progress just because it's not reinforced by the scale. Example: I've been around the same weight for several months- hit it back in November, rebounded a little over the holidays and am back at that point. But, my body fat is LOWER now than when I original hit this weight. My clothes also fit a bit better than they did a few months ago and I've recorded some small reductions in my measurements. If I only paid attention to the scale, I'd be frustrated and wondering what the point is - but these little things show me that the efforts I've put in over the past few months HAVE made a difference!