I don't need to lose weight--I'm a male who probably is slightly underweight for a woman of my height--but I do have the little roll of fat around the middle. One day I noticed that it was smaller than it used to be. I noticed this about THREE YEARS after I started regular bicycle commuting. The moral, to me, is that you will not lose weight dramatically, but it will come off as it went on, gradually over a long time. Of course everyone's metabolism is different. Maybe you should weigh yourself only every six months.
If I were trying to lose weight, the next thing I would do after regular bicycle commuting would be to give up all refined food, especially white sugar and white flour. You probably have heard that. Even if it doesn't help, it certainly won't hurt, and it might help. One won't die from a cookie deficiency, but could become ill from a vegetable deficiency. As Jack LaLanne says, if man makes it, don't eat it.