If you just got started with Natural Cycles on Prevent, it's normal to get more red days in the beginning. Natural Cycles is getting to know your unique cycle and probably hasn't detected your ovulation yet. It is highly individual how fast ovulation can be detected, but it usually takes 1-3 full cycles of measuring according to our guidelines. So be patient and keep measuring, the red days will decrease with each cycle as the algorithm gathers more data on you.
Other reasons why you might get you more red days are:
After hormonal contraceptives
Our data shows that those who have previously taken hormonal contraception and are just starting with Natural Cycles experience more red days in the beginning. This is because it can take a while before your body starts ovulating again, and the first cycles are often highly irregular. Since the first ovulation can come early or late, without warning, you will receive red days until it happens. Read more here.
Fluctuating temperatures
If your temperatures fluctuate, the algorithm could give you more red days since it becomes more difficult to detect ovulation due to the variating temperatures. These temperatures make it harder for the algorithm to track your cycle. To help our algorithm learn more about your cycle and accurately find ovulation, please measure according to our guidelines and use the "exclude" temperature if needed.
Exclude your temperature only if you feel that something was out of the ordinary for you, and you feel differently this morning because of it.
Make sure that you always measure as soon as you wake up, and mark the temperature as "excluding" if you sleep more or less than usual (± 2 hours). Also, mark the temperature as "excluding" due to 'Alcohol' if you drink alcohol and feel hungover when you wake up or if you're ill. Read more about how and when to measure.
Irregular cycles or anovulatory cycles
Some women have more irregular cycles than others. Ovulation rarely occurs on exactly the same day every cycle, but for some women, it varies a bit more than a couple of days. In some cycles, ovulation may not occur at all for various reasons; this is known as anovulatory cycles. These two cycles are especially common if you have recently given birth, breastfeeding, or were using hormonal birth control. Read more here.