OMG - Fatty Fatty two by four........?

I am 14 1/2 and VERY active with sports. I have been lifting weights as part of my soccer and basketball programs. However, I have noticed that I have been gaining weight...like around 7 lbs.! I know muscle weighs more than fat but geez I don't want to look like a freakin' hulk either...YIKES. I am a little over 5'10" and just weighed myself last night at 133. Is this a normal amount to gain. I do not eat poorly and I am always moving and active......help please!! Thanks!