Last Updated: July 23, 2026

About Lovesafe Calendar Estimates

Lovesafe Calendar is a personal cycle-tracking and estimate tool. It uses information you enter, your completed cycle history, and your selected cycle range to display estimated cycle timing.

Estimates can vary and cannot confirm ovulation, fertility, pregnancy, or pregnancy prevention.

Lovesafe Calendar is not a medical device and does not provide medical diagnosis or treatment.

How Estimates Are Created

Ovulation Estimate

The Ovulation Estimate shows an estimated cycle day based on completed cycle history. If no completed cycle history exists yet, Lovesafe Calendar uses the midpoint of the selected cycle range.

Estimated Next Period

The Estimated Next Period is based on average completed cycle length. If no completed cycle history exists yet, Lovesafe Calendar uses the selected cycle range.

Safe and Not Safe Day Displays

Safe and Not Safe Day Displays are estimates based on cycle timing and the selected cycle range. They may change from cycle to cycle and should be used as a planning guide, not as an exact prediction or guaranteed method of pregnancy prevention.

Important Disclaimer

Lovesafe Calendar provides educational information and personal cycle estimates based on user-entered data.

The app cannot confirm whether ovulation has occurred and cannot determine whether pregnancy is possible on a particular day.

Do not rely on Lovesafe Calendar as your only method of contraception. Speak with a qualified healthcare professional about contraception, fertility, irregular cycles, pregnancy concerns, or other health questions.

Sources

American College of Obstetricians and Gynecologists

Fertility Awareness-Based Methods of Family Planning. Information about fertility-awareness methods, menstrual-cycle tracking, ovulation timing, fertile windows, and the limitations of calendar-based estimates. View source

American College of Obstetricians and Gynecologists

The Menstrual Cycle: Menstruation, Ovulation, and How Pregnancy Occurs. Provides general information about the menstrual cycle, including menstruation, ovulation, and how cycle timing relates to pregnancy. View source

Additional Peer-Reviewed Research

Lovesafe Calendar was developed using published research related to menstrual-cycle timing, fertility awareness, cycle variation, and reproductive health.

The Timing of the “Fertile Window” in the Menstrual Cycle: Day-Specific Estimates From a Prospective Study. Wilcox AJ, Dunson D, Baird DD. BMJ, 2000. View Research Source  

Menstrual Cycle Length and Patterns in a Global Cohort of Women Using a Mobile Phone App: Retrospective Cohort Study. Grieger JA, Norman RJ. Journal of Medical Internet Research, 2020. View Research Source

Real-World Menstrual Cycle Characteristics of More Than 600,000 Menstrual Cycles. Bull JR, Rowland SP, Scherwitzl EB, et al. npj Digital Medicine, 2019. View Research Source

Menstrual Bleeding, Cycle Length, and Follicular and Luteal Phase Lengths in Women Without Known Subfertility: A Pooled Analysis of Three Cohorts. Najmabadi S, et al. Paediatric and Perinatal Epidemiology, 2020. View Research Source

A Mid-Cycle Rise in Positive and Drop in Negative Moods among Healthy Young Women: A Pilot Study. Hromatko I, et al. Brain Sciences, 2023. View Research Source 

Medical Questions

Lovesafe Calendar does not provide medical advice. Contact a licensed healthcare professional for questions about symptoms, cycle changes, contraception, fertility, pregnancy, or treatment.