Exercising/Eating Healthy but no Weight Loss

Hey guys!

This is my third week of eating healthy and exercising (6 times a week) I burn around 400 calories each workout session. I recently gained a bit of weight and decided to get rid of it (again). Last year I successfully lost 20 pounds in about three months. Unfortunately I started college and gained most of it back, so naturally I wanted to lose it again. The first two weeks were fine, I lost 4-5 pounds. But the this third week is killing me, I'm not getting any results, and I've even amped up my workout regime. I eat healthy all day as well. I have cereal (Special K Red Berries) every morning with a piece of fruit, then I workout, then I have fat free greek yogurt after my workout, for lunch I have salad with 3 kalamata olives cucumbers carrots and fat free dressing, then later on I have fruit as a snack, and sometimes I have pretzels like 1 or 2 of the pretzel rods, and for dinner I usually have "fake meat" since I'm vegetarian with vegetables and some other whole grain. I eat around 1200-1500 calories a day so I really don't understand why I'm not losing weight, its very frustrating. I'm doing exactly what I did last year, but not getting the same results. Also I don't need too many calories because I'm short, I'm only 4'11 and I'm 19 years old. My start weight was 140 and I'm down to 134.8, but like I said the scale hasn't budged.

Please help!