I feel your pain. I have decided to take my measurements because I know I am fitter but nothing shows up on the scale. I discovered that for every day I had a deficit of calories, I had a surplus of calories. I now aim for a 500 calorie per day deficit (except last week I traveled and my weight slipped up again!)
If you go by math alone, at 140 pounds you burn about 1,400 calories with minimal activity. With a 500 calorie burning work out, your total expenditure is about 1,900 calories per day. To lose one pound a week, you would have to eat 1,400 calories every day. If you take two days off exercising, it will take 9 days to lose one pound. It would take 18 days to lose two pounds. I agree with Nancy, it will take a while to see your efforts.
I have to congratulate you on your consistency. That is what I struggle with. Given time, if you are consistent, you are bound to lose (win?)
The scale doesn't measure improved health, reduced pain, and a better lifestyle.