We recommend that you use OvuSense for a minimum period of 6 hours during sleep, and the data to be downloaded within an hour or so of when you remove the sensor and wash it after waking up.  

When you press Connect to download data from your Sensor, OvuSense collects a window of the last 13 hours 40 minutes of data immediately before the download.   If you try to download twice within that window OvuSense will give you a message saying you've already downloaded and won't allow you to download again until that window has passed.   If you attempt to download again after the window has passed you are quite likely to get a zero result as you are downloading mostly or entirely room temperature data.

To get back in sync, please don't download again today, use OvuSense when you sleep again and then download when you wake up.