Always remember that muscle is heavier than fat. I think the best way to measure your progress is by taking weekly pictures or measurements don't worry about the number on the scale. Also if you are feeling good and still making gains in the gym It sounds like you are doing well. The only way to start burning muscle would be to not eat enough protein so make sure you are getting enough and it should not be an issue. Congrats on your progress so far and keep it up!