I do 90 minutes of excerise on my bike most days, and 45 minutes on the days I can't. It's been almost two weeks since I started. I don't feel any weight loss, but I do feel a lot more energetic and better.
I am female, age 21, and a size 14. Just above 11 st. My pulse rate can go up to 130-150 so I know I've been working hard. My diet, well, I don't overeat, but I have a tendency to eat tooo little in a day. Chocolate, fried food etc I will probably touch once in two weeks.

It is healthy to lose 1-2 pounds per week with a healthy diet and exercise.....
You mentioned not eating enough in a day....this can actually cause you to gain weight or maintain your weight since you have stating working out and need more fuel to function. Think about it: You put gas in your car to make it go...too little you won't get too far, too much it overflows out of the tank and on to you, your clothes and side of the car....Point is: choose the right fuel, the right amount 1200-1600 calories per day, eat every 3-4 hours a "snack size" meal to keep insulin levels regulated and metabolism functioning properly and eat breakfast within the first 1-2 hours of waking up. This kick-starts you metabolism and wakes the body up to do work and start burning calories. By skipping meals you slow the body down, confuse it and it may think you are in "feast or famine" mode and hold onto anything you do put into your body to store for energy later when you have skipped meals or have not fueled the body enough....People think calorie restriction and meal skipping will help them lose weight...but in reality in can do the opposite! So start eating small meals every 3-4 hours, try to eat plenty of fruits,veggies, lean meats, whole grains and low fat dairy products. Check out the USDA website and the American Dietetic Association website for more info on healthy eating.

I think you could easily be gaining muscle from all the exercise you are doing or your body is trying to shut you down which it does if you overdo it. I would give it another 2 hard weeks and you will probably feel and see results