How accurate is a conception date calculator?

It provides an estimated date based on standard medical formulas. For a precise date, consult a healthcare provider.

Can I calculate conception date using ultrasound?

Yes, by subtracting 252 days from the date of the ultrasound scan, which estimates fetal age.

What is the difference between LMP and conception date?

LMP is the first day of your last period. Conception typically occurs about 14 days later during ovulation.

Pregnancy Conception Date Calculator

Estimate Conception Based On: Select Date:

Understanding Your Conception Date

Your conception date is the estimated day when fertilization occurred. This is generally around two weeks after your last menstrual period (LMP). While it’s hard to know the exact moment of conception without assisted reproduction, this calculator gives you a reliable estimate using well-established methods.

How the Conception Date Calculator Works

Due Date: Subtracts 266 days from the expected delivery date.
LMP: Adds 14 days to the start of your last period.
Ultrasound Date: Subtracts 252 days to approximate ovulation.

Trimester Timeline Overview

1st Trimester (Weeks 1–12): Hormonal changes, morning sickness, organ formation.
2nd Trimester (Weeks 13–26): Baby’s movements begin, anatomy scan usually performed.
3rd Trimester (Weeks 27–40): Rapid growth, preparation for birth, and regular checkups.

Tips for a Healthy Pregnancy

Begin prenatal care early and attend all appointments.
Take folic acid daily (400–800 mcg).
Eat a balanced diet rich in iron, calcium, and protein.
Engage in light, doctor-approved physical activity.
Avoid smoking, alcohol, and certain medications.

Why Knowing the Conception Date Matters

Knowing your estimated conception date can help with scheduling ultrasounds, monitoring development milestones, and predicting the due date. It’s also useful for determining maternity leave and preparing emotionally and physically for childbirth.

Frequently Asked Questions

How accurate is a conception calculator?
It’s an estimate. Conception may occur a few days before or after ovulation. For most, this is accurate within a few days.

Can I get pregnant outside my fertile window?
It’s unlikely. The fertile window is typically a 5-6 day period around ovulation, but sperm can live inside the body for up to 5 days.

Can ultrasound change my conception estimate?
Yes, early ultrasounds provide one of the most accurate dating methods during pregnancy.