Enter your cycle details to visualise your fertile window and estimate conception probability across the cycle. Based on reproductive medicine science.
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Generated at traitgen.com, Free genetics education. Not medical advice.
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⚠️ Educational only. Probability estimates based on genetic models, not medical advice.
Sperm can survive inside the female reproductive tract for up to 5 days, which is why intercourse before ovulation can still lead to conception. The egg, however, is only viable for 12–24 hours after ovulation — making timing critical.
Conception probability is peak during the 6-day fertile window, which includes the 5 days before ovulation and the day of ovulation itself. This is governed by hormonal cycles: LH surges trigger egg release. The Ogino-Knaus method estimates these milestones.
The biological window dictated by egg viability (12-24 hours) and sperm lifespan (up to 5 days) in optimal cervical fluid.
Luteinizing Hormone (LH) surges from the pituitary gland trigger mature follicles to release an egg into the fallopian tubes.
While ovulation typically occurs 14 days before the next cycle, follicular phase lengths vary, shifting the fertile window.
A historical calendar-based fertility method that maps statistical averages to predict fertile phases.
Track changes in cervical mucus (becomes clear and stretchy like egg whites), monitor basal body temperature (shifts up slightly), or use luteinizing hormone (LH) urine strip tests.
Very unlikely. Conception requires a viable egg to be fertilized. If intercourse occurs more than 5 days before ovulation or 24 hours after, fertilization cannot take place.
Regular cycle length (between 21 and 35 days) is a healthy indicator of regular ovulation. Very short or long cycles can sometimes indicate irregular ovulation.
They provide good statistical estimates based on averages. However, because stress, travel, or hormones can delay ovulation, calendar methods are not 100% reliable.