Weight loss is a funny old business, some people lose it quick, some not so quick. Try and look at other - non scale - ways of measuring your progress. Are you losing inches? Do you feel better? Are your clothes getting loose?
All of this means you are on the right track.
Muscle does weigh more than fat so you could be getting smaller while not seeing a difference in the scales. If you are tracking your workouts maybe post on the Fitness boards and see what the experts think.