Measuring on the weekends is a common reason for fluctuating temperatures. It can result in an unnecessary amount of red days for our Prevent users and many brown days for our Plan users.
We recommend five temperature readings a week. You should measure at roughly the same time each morning, as this will give you the best results and allow the app to pinpoint your fertile window correctly.
If you would like to measure on the weekends, we recommend that you set your alarm at the same time as on the weekdays (and go to bed around the same time) to ensure that you are giving the app accurate data. Measure at roughly the same time every morning, no more than 2 hours earlier/later than you measure during the weekdays after also having slept the same amount of hours as you usually do during the week.
What you can do is to set your alarm at the same time as your weekdays, measure as soon as you wake up, and then fall back asleep - you can read the value later.
Please keep in mind that you must always measure as soon as you wake up before you snooze, sit/get up, or check your phone, etc.