Regular cycle + OPK
- Input
- Ciclo de 28 dias + teste de LH positivo
- Expected output
- Janela fértil confirmada: 24–36h antes da ovulação
Good strategy for those trying to conceive with predictable cycles.
ovulation signs fertile window
Ovulation Signs: How to Identify the Fertile Window
The body produces observable physical signs before and during ovulation. Combining them with calendar calculation increases reliability in identifying the fertile window.
Continue in the tool
Open full toolThe four main signs
- Cervical mucus: near ovulation, it becomes clear, stretchy and slippery — resembling raw egg white. It is the sign most directly correlated with fertility.
- Basal body temperature (BBT): rises 0.2–0.5°C after ovulation. Useful to confirm ovulation occurred, not to predict it.
- LH surge: detectable in a urine test 24–36 hours before ovulation. Most accessible predictive sign.
- Ovulation pain (mittelschmerz): lateral pain or discomfort in the lower abdomen. Present in 20–40% of people; not universal.
Combination strategy
Full tool FAQ
Ovulation occurs approximately 14 days before the next expected period, regardless of total cycle length. In 28-day cycles, that is around day 14. In 35-day cycles, around day 21. This calculation is an estimate for regular cycles; irregular cycles require complementary methods.
Frequently asked questions
Is cervical mucus reliable on its own?
It is a good indicator, but ideally should be combined with BBT or LH testing for greater accuracy, especially in irregular cycles.