1500 cals and 45 minutes a day could be too low for your current weight - as counter-intuitive as it is, perhaps you need to eat more. If you try it, you'd have to give it a go for 4-6 weeks. I recently spent 5 weeks not losing anything while eating at my appropriate level (after two months of all you can eat buffet style food at a language program) and it took my body that long to adjust and start dropping the pounds.
Also, keep track of your measurements. Even when we're not losing "weight" we could be losing inches - and that's what we're here to do, after all, is lose the fat, not the weight. If you keep in mind that they can be different things, you'll see other changes.