It's only been three weeks, so be patient, it takes longer for some people to lose weight than others. It seems like you're doing things right, make sure you're also getting the proteins and carbohydrates in there. Because of fad diets, most people think right away, "Carbs are bad!" But in actuallity, carbohydrates are necessary for energy. Just make sure you eat the right proportions of everything, and make sure your diet is actually balanced. (Like certain vitamins make certain minerals absorb better, etc.)
But yes, you will gain weight in muscle, which is a good thing. A few years ago, I weighed...very little, actually underweight, which was due to a lack of muscle mass, and had gained about 10 pounds in a year after doing exercises to increase strength, but was still about the same measurement around.
I'm not a doctor, so I can't tell you if there's any defficiency or anything, but it seems as if you're doing things right but are just expecting certain results immediately. But, like I said, I'm not a doctor.

It will take longer than three weeks to see results, women have a harder time losing weight than most men do. Keep working at it. If you've had kids, or even if you havn't, losing 20 more lbs is alot. I had Smartlipo done to help with cellulite and lose skin. It gave me more confidence in my body. I have been really active most of my life but now I feel sexy. I play raquet ball, swim, run...pretty much anything I can to be active. Sometimes it's not enough.

First, congratulations on making the decision to get exercise. It does not sound like you are in that poor of shape.

Here are a couple of observations:

1. You are doing too much cardio. Since you are not in that poor of shape, your body is fairly efficient. If you do that much cardio, you will be operating in the aerobic range, which is great for the heart, but does not burn fat. I would reduce your cardio to no more than 4 times a week, and not for more than 30 minutes each shot.

2. I would add some upper body weight training exercises. Weight training has a better affect on the basal metabolic rate than cardio does; that is, you will burn more calories while you are at rest when you workout with weights.

3. You give your caloric intake, but you do not say how often you eat, nor do you say how you are getting your protein. You may find it is better to have 5 meals a day rather than the normal three. Try not to consume more than 400 calories at any meal.

4. Make sure you are getting some fats, and make sure you are getting omega IIIs and omega 6s. Fish oil and flax oil are great ways to do this.

Keep up the good work. I am sure you will see results soon.

Ray

i have the same problem ive been loseing the same 75 lbs for 10 years now but i dont want to be on here forever so to make it short. This last time i tryed sugar busters and i lost 75 lbs just power walking eating just the right carbs flex oil omega 3 everything worked just fine but then i had a rough time with my marriage and my old friend( fatty foods) came back and i gained 67 lbs ...Recently things have gotten better and i found myself really uncomfortable ive had fatty liver in the past and fearing for my health and feeling my kids needed me to be healthy and for myself i decided to get busy ..So here i am again on May 17th 2009 i started to excercise again and i love it..My thing is power walking and just eating the right foods all day long i never over eat and i feel if it worked before it will again .. thats just it its not working here it is june 15 and ive only lost 10lbs .Im getting so obssessed with that freakin scale i want to throw it out the window. I don't know how to eat the right foods i think but either way i need help!