You can rely on our devices' results starting the very first day of use. In the beginning, you will see more yellow and red days because Daysy and Ladycomp are still learning your unique cycle. You will see more green days as they come to understand your cycle and can narrow down your fertile window. The more regularly you measure, the better.
What is the best way to measure?
For optimal use of Daysy, we recommend that you should have slept sufficiently (at least one hour) before the measurement. It is important that You take your temperature immediately after waking up, before getting up and becoming active. Measure below your tongue, with your mouth closed, and keep the device steady while it is measuring.
Is there a delay between when I take my temperature with Daysy (or Ladycomp) and when it shows my fertile days?
Daysy is not a simple thermometer. Rather than just recording your basal body temperature (BBT), Daysy analyses your data using an extensive database and a proprietary algorithm built on over 30 years of research and several scientific studies.
Daysy’s algorithm is based on more than five million menstrual cycles and can reliably determine your fertile and infertile phases. It uses your daily temperature readings and menstrual data to learn your unique cycle patterns.
The algorithm’s accuracy has been scientifically validated. In one study, researchers evaluated 107,000 cycles (temperature and menstruation data) from 5,328 women in Germany and Switzerland over a ten-year period. The independently reviewed results showed that Daysy achieves a 99.4% accuracy in distinguishing between fertile and non-fertile days.
So, rather than showing “lag,” Daysy continuously updates its predictions as it learns more about your cycle, providing both predictions of ovulation and confirmation once ovulation has occurred.
Does Daysy’s accuracy depend on consistent conditions?
You can always rely on Daysy. However, to get the best results, use Daysy daily right after waking up, before getting out of bed or becoming active. For optimal accuracy, it’s best to have at least one hour of continuous sleep before taking your measurement. If you need to skip a reading after a sleepless night, don’t worry. Daysy will still reliably display your fertility status. Depending on where you are in your cycle, Daysy’s algorithm will adjust accordingly.
Maintaining consistent conditions helps ensure the most accurate results.
Do smoking and alcohol affect Daysy's readings?
Smoking does not influence Daysy’s readings. However, alcohol can affect your basal body temperature, especially if you’ve had more than your body is used to. If you wake up feeling the effects of alcohol (headache, dehydration, or just feeling off), it’s best to skip your temperature reading that morning. If you feel fine, you can measure as usual.
How does Daysy react to increased temperatures, e.g. fever?
Fever can also influence your readings. A fever is generally defined as a body temperature of 38°C (100.4°F) or higher. When this happens, your temperature curve will appear unusually high, and the DaysyDay app will alert you that your temperature is elevated. It will also recommend checking your temperature with a standard medical thermometer. For your safety and data accuracy, any temperatures above 37.8°C (100.4°F) or below 35°C (95°F) are automatically excluded from the algorithm and will not affect your fertility calculations.
In general, you should skip measurements during illness and while you are taking medication that can have an influence on your body temperature or cycle. If you have doubts, contact your doctor or our customer service team.
How do LadyComp and Daysy help me understand my ovulation, hormone levels, and fertility?
Thanks to their unique algorithm, LadyComp and Daysy provide you with deep insights into your menstrual cycle. These intelligent fertility monitors can show you whether you are ovulating, if your progesterone levels may be too low, or if your luteal phase is shorter than optimal.
LadyComp, in particular, goes a step further by offering:
- Ovulation forecasts at the beginning of your cycle to help you plan ahead.
- Identification of your most fertile days for optimal timing of intercourse.
- Confirmation of correctly timed intercourse relative to ovulation.
- Monitoring of progesterone levels during the luteal phase, which is crucial for proper embryo implantation.
- Early pregnancy detection and calculation of pregnancy weeks and your expected due date.
