DelaFertility · 3 min read
Fertile window explained
The fertile window is the part of a cycle when pregnancy is most likely. For people trying to conceive, combining calendar patterns with body signs builds a fuller picture than any single prediction.
Sources and editorial standardsGeneral information, not medical advice.
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What the fertile window means
Ovulation usually happens once in a cycle. The days of highest probability generally come before and around ovulation, but calendar dates are not exact. ACOG explains that pregnancy can occur from intercourse up to five days before ovulation through one day after, because sperm may survive several days and an egg may survive about 24 hours.
Signals that can add context
Calendar timing and body signs each add context, and together they can narrow the picture. No single sign pins the exact ovulation day.
Cycle history
Past cycle lengths are one of the most useful inputs for estimating a future window, and the longer your record, the more it shows. Stress, illness, travel, postpartum changes, and other factors can still shift timing.
Cervical fluid
Some people notice cervical fluid become clearer, wetter, or stretchier near ovulation. Logging this can make patterns easier to see over time.
Basal body temperature
Basal body temperature often rises after ovulation. A sustained shift can add retrospective evidence that ovulation may have happened. Temperature is at its best in hindsight: it confirms a pattern more than it forecasts fertile days in advance.
Ovulation tests
Ovulation predictor kits can detect a hormone surge that often happens before ovulation. Logging test results beside symptoms and cycle history can give a fuller picture. A positive test is indirect evidence of a hormone surge, not proof that an egg was released. Tests can produce false positive or false negative results.
How Dela helps
Dela brings these signals into one private place: cycle history, fertile signs, temperature, ovulation tests, symptoms, and notes. The app can help you review timing with more context while keeping your reproductive data under the controls described in Dela's privacy policies.