💡 Conception Date Calculator
Select your dating method and enter the relevant date to find your estimated conception date.
How Conception Date Is Calculated
The difference between gestational and embryonic dating
In natural conception, the conception date is estimated by working backwards from the last menstrual period (LMP). Ovulation typically occurs 14 days after LMP in a 28-day cycle, and fertilisation happens within 24 hours of ovulation. Therefore, conception date ≈ LMP + 14 days.
IVF Dating — The Most Precise Method
In IVF, the exact fertilisation date is known from laboratory records. For a Day 5 blastocyst transfer, fertilisation was exactly 5 days before transfer. For a Day 3 transfer, fertilisation was 3 days before transfer. This makes IVF conception dating more precise than natural cycle dating.
Why Gestational and Embryonic Age Differ
Gestational age (from LMP) is always 2 weeks greater than embryonic age (from fertilisation). At a "6-week scan," the embryo is actually only 4 weeks old from conception. Both are valid dating systems — doctors use gestational age; embryologists use embryonic age in IVF.
Conception Date ఎలా Calculate అవుతుంది?
Gestational మరియు embryonic dating తేడా
Natural conception లో, LMP నుండి backwards calculate చేసి conception date అంచనా వేస్తారు. 28-day cycle లో ovulation సాధారణంగా LMP తర్వాత 14 రోజులకు జరుగుతుంది, fertilisation ovulation తర్వాత 24 గంటల్లో జరుగుతుంది. కాబట్టి conception date ≈ LMP + 14 రోజులు.
IVF Dating — అత్యంత Accurate పద్ధతి
IVF లో lab records నుండి exact fertilisation date తెలుసు. Day 5 blastocyst transfer కి, fertilisation transfer కంటే 5 రోజుల ముందు జరిగింది. Day 3 transfer కి, 3 రోజుల ముందు. అందుకే IVF conception dating natural cycle కంటే more precise గా ఉంటుంది.
Gestational మరియు Embryonic Age ఎందుకు వేరుగా ఉంటాయి?
Gestational age (LMP నుండి) ఎప్పుడూ embryonic age (fertilisation నుండి) కంటే 2 వారాలు ఎక్కువగా ఉంటుంది. "6-week scan" లో embryo actually conception నుండి 4 వారాల వయస్సు మాత్రమే ఉంటుంది.
Frequently Asked Questions
How is the conception date calculated from a due date?
The EDD is calculated as LMP + 280 days. Working backwards, the conception date is approximately EDD minus 266 days. Because ovulation can vary by several days, a ±3 day window is given for the conception date estimate.
How is conception date calculated for IVF?
In IVF, the exact fertilisation date is known. For a Day 5 blastocyst transfer, fertilisation occurred 5 days before transfer. For a Day 3 transfer, fertilisation occurred 3 days before transfer. The conception date is therefore precisely known in IVF.
What is the difference between gestational age and embryonic age?
Gestational age is measured from the first day of LMP. Embryonic age is measured from the day of fertilisation. Gestational age is always approximately 2 weeks greater than embryonic age. In IVF, both dates are precisely known.
Can I know exactly when I conceived?
In natural conception, the exact date is rarely known — this calculator provides an estimate. The conception window is typically ±3 days. In IVF, the exact fertilisation date is known from laboratory records. First-trimester ultrasound gives the most accurate pregnancy dating.
Does conception happen on the day of intercourse?
Not necessarily. Sperm can survive for up to 5 days. The egg survives only 12–24 hours after ovulation. This is why the exact conception date is an estimate in natural conception.
How accurate is this conception calculator?
Most accurate for IVF transfer dates or first-trimester ultrasound dating. When based on LMP alone, estimates are within ±3–5 days for regular cycles. Call Mother Hospitals: 97059 93366.
మీకు ఉన్న సందేహాలు — జవాబులు
Due date నుండి conception date ఎలా calculate అవుతుంది?
EDD = LMP + 280 రోజులు. Backwards calculate చేస్తే conception date ≈ EDD minus 266 రోజులు. Ovulation vary అవుతుంది కాబట్టి ±3 రోజుల window ఇస్తాం.
IVF కోసం conception date ఎలా calculate అవుతుంది?
IVF లో exact fertilisation date తెలుసు. Day 5 blastocyst transfer కి, fertilisation transfer కంటే 5 రోజుల ముందు. Day 3 transfer కి, 3 రోజుల ముందు.
Gestational age మరియు embryonic age తేడా ఏమిటి?
Gestational age LMP నుండి, embryonic age fertilisation నుండి. Gestational age ఎప్పుడూ embryonic age కంటే 2 వారాలు ఎక్కువ. IVF లో రెండూ precisely తెలుసు.
Exactly ఎప్పుడు conceive అయ్యానో తెలుసుకోవచ్చా?
Natural conception లో exact date సాధారణంగా తెలియదు — ఈ calculator estimate ఇస్తుంది (±3 రోజుల window). IVF లో lab records నుండి exact date తెలుసు. First-trimester ultrasound most accurate dating ఇస్తుంది.
Intercourse రోజే conception జరుగుతుందా?
కాదు — sperm 5 రోజుల వరకు survive చేయగలదు. Egg ovulation తర్వాత 12–24 గంటలు మాత్రమే survive చేస్తుంది. అందుకే exact conception date natural conception లో estimate మాత్రమే.
ఈ calculator ఎంత accurate గా ఉంటుంది?
IVF transfer dates కి అత్యంత accurate. LMP మాత్రమే use చేస్తే regular cycles కి ±3–5 రోజులు accurate. Irregular cycles కి ultrasound dating use చేయండి. Call: 97059 93366.