Muscle weighs more than fat, so if you've replaced some of your fat with muscle, plus if you've built up the muscle you already have, it's going to weigh more (muscle also retains a little more water).
You're hungrier because, pound for pound (plus the extra exercise) muscle burns more calories....you've increased your metabolic rate by gaining all the extra muscle mass.
Have you measured your waist?? and your bust size?? If you are gaining "fat" you will notice it in those areas....if they are not much different then I'd keep an eye on it but not be overly concerned. How do your clothes fit?? Same? Better? or too tight?
Your muscle mass should level out (even if you lift heavily) over time and so the weight gain will also level out....unless you eat more than you burn off
Congrats on a great, healthy new bod
Thoreau said, 'A man is rich in proportion to the things he can leave alone.'