I recently got diagnosed with endometriosis after a year of trying to conceive. I've had 3 chemical pregnancies and after reading you are more likely to have low progesterone due to the estrogen dominance that comes with endometriosis, I thought this would be a good way to check. The app was so frustrating to use. It kept not reading the answer and when it finally did it seemed wrong (positive when it was darker compared to the previous day when it said negative). So now I don't trust the results at all. You also can't delete a reading and scan it again to make sure it wasn't an error. Very disappointing experience that caused much more stress