If you've been walking the same distance for a month and no weight loss, it's possible that you aren't walking long/far enough each day. Your body gets used to doing the same thing every day, so just comes to expect it.
You should also take a look at what you're eating. 0.5 to 1 mile is not a lot of exercise, so you may be taking in more calories than you're burning.
How long have you been walking like this? It could be time to try adding more to the routine like walking with weights?