Natural Cycles uses your unique basal body temperature (BBT) readings and LH test results (optional) to pinpoint where you are in your monthly cycle - i.e. time of menstruation, ovulation, when you are likely to be fertile (red days) or not (green days).
Each person who menstruates has a unique menstrual cycle pattern. The cycle length, the day ovulation occurs, the amplitude of the temperature rise, the base temperature in the pre- and post-ovulatory phases, and the overall shape of the temperature evolution throughout the cycle are all parameters that vary from person to person.
Natural Cycles can accurately capture every unique cycle by taking cycle irregularity, temperature fluctuations, the recent usage of hormonal contraception, ovulation day variation, sperm survival, and several other essential factors into consideration.
The Menstrual Cycle
Your cycle starts on the first day of menstrual bleeding and is on average 29 days, but as stated above, this can vary from person to person.
It consists of three phases:
- The follicular phase - is estrogen-rich and cooler (average temperature for our Cyclers: 36.23°C / 97.21°F)
- The ovulation day - is the day you can get pregnant. Two well-known biological indicators of ovulation is a temperature rise of 0.2-0.45 °C and a rise in luteinizing hormone (LH) roughly 48 hours before it. (Average ovulation day for our Cyclers: CD 17)
- The Luteal phase - progesterone dominates and ‘warms’ the body (average temperature for our Cyclers: 36.58°C / 97.84°F)
Natural Cycles offers insights into an individual's cycle, so you can gain an overview of the most important statistics to help you manage your health. This is shown in the 'My Cycle' tab in the app, which is updated frequently as you add more data.