excersise dvds

You have just been doing it for a week, your gain is probably water and your body adjusting to the workout. Keep it up, you will lose the fat and notice changes with time.

First, it's impossible you gained 3 lbs of muscle mass in one week. Even bodybuilders needs months for that and usually they are not on a limited calorie intake.
BUT, it is definitely possible your body retains water. It happens to me all the time, when I start a new workout. Give it a bit longer and your body will release it again, once it gets used to the workout.
It's said 80% diet, 20% exercise. That's the best way to get rid of the fat.
Also, check your calorie intake. Are you weighing your food or are you just assuming how many cals you get in daily? Sometimes you can go very wrong, if you don't measure everything. Also make sure you eat enough. That sounds counterproductive. But I've seen it a lot on here that people want too much at once and limit their calorie intake drastically, while working out like crazy. Remember, this is a slow process and it takes time to figure out what works for your body.

I go up and down 2-3 lbs often. Its mostly fluid/sodium bloat. Make sure you weigh at same time period. Morning weight is different than evening. If you keep going up I would be concerned. But I bet you'll be back down in 2 weeks.