First, please make sure that all your address information is correct (go to "my account" on the menu). If you have provided at least a partial address, particularly with the postal code, that will usually give an approximate (and sometimes very accurate) location.
If that doesn't do it, please set your own location on the map. Go to "my account" and click on the "map my location" tab. Zoom in or out, move around, and click where you actually live, and then press the "submit" button.