Good choice..^^
Note: your body fat percentage is going to be completely dependent on your diet,, not AAS.. Gear won't make you fat (it can make you hungry though).. On a first cycle you could put on way more then 10 pounds. You could put on 20-25 (or 33 like I did).. And this isn't fat weight,, again fat is based on diet.
Now this isn't pure "new" muscle weight either, when you train with gear, you'll put on volumizing weight. Your muscles will fill with water, blood, glycogen stores,, you'll be retaining more nitrogen, blood volume etc.. Your muscle cells will grow ,, your probably not gonna gain new muscle fiber and cells (that takes a long time with training myofibrillar fibers),,
So all of this is gonna result in an increase of weight (it's not fat)