Can't revise menstruation data from >3 days prior Your product doesn't allow you to go back to revise menstruation data if it has been 3 days since the entry. This makes it extremely frustrating if you've already logged multiple months of data, and now have to do a factory reset in order for Daysy to accurately track your cycle. I have contacted Daysy about this issue, and have not been given any way to fix this issue without reseting the device and starting its tracking from day 1. I haven't found any cases online of other customers who have been able to resolve this issue either.

Definitely not worth your money This has to be my biggest Amazon purchase regret and I wish I could return it after 4 months of trying. It is so hard to use, hard to remember how to use, the app sucks, and this technology is not nearly as smart as it leads you to believe. You can’t track your period start days unless you remembered to take your temperature that morning and you can’t go back and update information from over 3 previous days so if you forgot to take it your temperature you’re screwed. You have to manually sync the Daysy to the app and the app to the Daysy- this is fairly straightforward but not something you’d expect from a €300 device. The app feels outdated and pales in comparison to competing apps like Flo. I sincerely do not know how this has 5 star reviews on every platform. If it were €20, it’s totally worth the money. Maybeeee €100. But €300 is ridiculous for how cheap it feels, how outdated it is, and how complicated it is. I seriously doubt this was even made by women for women.

I can't imagine my life without the… I can't imagine my life without the Daysy! I'm super grateful for this device and trust its reliability. I value my cycle more since using the Daysy, and I love not being able to worry about condoms since I'm good to go on green days. My partner gets excited for my green days, and the waiting makes the experience even more special, without the worry!

Love it, but could be better.. Love it, but it could be better. I noticed I’m missing readings because I’m half asleep and I think it’s taking my temp but come to find out that I accidentally clicked the button twice and it was trying to sync instead of take temp.. Should probably change the blue tooth connection color and temp reading color. When you’re half asleep they look the exact same. Also, when using the app you can’t make a note or update sexual activity if it was a week ago. What’s up with that?

Works extremely well Daysy helps me monitor my fertility for preventing pregnancy, and it has worked perfectly so far. The app is great and I have had no issues with the device or the app. I love being able to download the charts and analyze my biology. Once I got a higher number of red and yellow days, so I reached out to customer support. Within one business day someone responded and provided an in depth analysis and advice.