If you were a bodybuilder, you would be the happiest person on the planet, but I am assuming you are not. When you do everything “right” for the first time (eating, supplementing and training), muscle comes swiftly. And if fat loss is your primary goal, the muscle gain should rapidly plateau. I will admit that your gain seems extraordinary and should not continue unless you had previously lost a significant amount of muscle through sickness, very low calorie dieting or a long layoff from resistance training. If this is the case, you would be experience what we call "muscle memory." In this state, when you resume normal eating and/or activities (especially weight training) after a long layoff, your body very quickly restores the lost muscle. When the body has recouped its losses, gains dramatically slow.
All that said, except for the acute issue mentioned above, if your goal is primarily fat loss, you should start losing net pounds within the first four weeks of your program. If not, your calorie deficit is not large enough. Therefore, increase your movement and/or decrease your food intake and the pounds will start flying off. And keep in mind that adding a little muscle is a good thing because it increases your calorie burn, helps you look more eye-catching and makes daily life easier.