Pregnancy Conception Calculator
Conception (medically) involves fertilization and implantation; for timing estimates this calculator treats the primary estimate as fertilization around ovulation. Sexual intercourse in the several days before ovulation can lead to pregnancy because sperm may remain viable about 3–5 days; the tool shows a 5-day backward window plus the estimated conception day.
Calculate based on
Ovulation ≈ cycle length minus luteal phase after LMP.
Clinical gestational age is usually counted from LMP.
Estimated conception date:
Possible intercourse window (sperm viable ~3–5 days):
Estimated due date (280-day rule from inferred LMP):
Irregular cycles and late ovulation increase uncertainty. Dating by early ultrasound is usually more reliable than LMP alone. This page is informational—not medical advice.