No muscle gain on a bulk?

I've been on a bulk from december. I added 150 cal and then additonal 50 about a month in. I've added carbs and protein no extra fat. I've gained 3kg. My scale says that I've gained 2% body fat which seems normal, but it doesn't show any mucle gain (the percentage stayed the same). I do know that those scales are not accurate but they should be accurate in tracking progress, right? It just seems weird that I haven't gained any muscle... I train about 5 times a week for about 1 and a half hour and I do really work hard in the gym. What could this be?

by Sara444 via Bodybuilding.com Forums - Female Bodybuilding