Is it normal to gain abit of weight?

Yes! That is a good sign. You are doing your exercises correctly. Muscle is very dense so it weighs a lot - so when you increase your muscle mass, your weight will go up. The good thing is that the more muscle you have, the more fat you will burn, even doing everyday activities! So once you build up your muscles, you will begin to burn off the fat pretty quickly.

Even cardio exercises can build muscle. It's normal to have some weight gain when you begin a new exercise program. Just stick with it and you will begin to see the results you want to see!

Don't worry, this is simply your current muscle becoming denser in order to prepare for the workouts they have to face in the future. They will not grow particularly much during the initla training phase, as they become denser rather than bigger, so it is puzzling where the weight goes. BUT they will begin to grow as you keep on training. Make sure that you keep up your program, it sounds spot on to me, so keep up the good work!

Most likely you have gained some muscle weight. Muscles are more dense than fat, so you most likely look slimmer even though you weight more. The combination of cardio and weight training helps burn fat and build muscle. It would have been nice if you had your body fat composition checked prior to the training. That way you can gauge how much fat you have lost and how much muscle you have gained. Why not start doing it now?

Well if you can't actually see the weight, it's just your muscles developing. Speak to your trainer or someone at the gym, they know best!

Muscle weighs more than fat, so perhaps you've just put on more muscle.
If its really worrying you though, you should see a doctor.