Unfortunately, running to lose weight takes some time. You are right, though, that running is definitely an efficient calorie burner. (In fact, it the most effective and efficient calorie burner of most cardiovascular activities!) But like many other things in life, seeing solid and healthy weight loss results takes times, and two weeks is simply not long enough to see substantial progress.
Before we get into the actual calorie burn of running, you need to first consider what you are eating. You might have heard this before but "you can't out exercise a poor diet." This simply means that, no matter how much you workout, if you throw good, healthy, and well balanced nutrition out of the window, you are not going to see the weight loss results you want. And the reason being makes sense - it is far easier to consume massive and excessive calories than it is to burn it off. Consider the following scenario: you ran a long run of ten miles at a steady 10 minute mile pace early on Saturday morning. That is excellent! You probably burned somewhere around 1200 to 1400 calories. But then, suppose you go out to dinner that night and are craving a dessert. You order a decadent chocolate brownie a la mode that comes in at about 900 calories. That one dessert almost offset what you burned during your run completely! And it is a whole heck of a lot easier to eat the dessert than it is to run the 10 miles.
Basically, when it comes down to it, you need to burn more calories than you are consuming in order to lose weight. The good news is that you need to make sure you have taken into consideration the amount of calories your body is burning without any exercise at all. Your body burns a significant amount of calories just to keep itself alive. So the real amount of exercise you need in order to lose weight definitely does not have to mean running tens of miles - as long as you are eating properly. It also depends on what kind of track you are running. A standard Olympic sized track equates to 4 laps equaling a mile. And for most, running one mile is about 100 calories burned. So if you think you need to burn an additional 300 calories a day to lose about a half a pound to a pound each week, then that would mean you need to run about 3 miles, or 12 laps on a standard sized track.