Discover your conception date or due date with ease.
Welcome to the Pregnancy Conception Calculator! This tool helps you estimate your conception date using your last menstrual period (LMP), due date, ultrasound results, or a known conception date. You can also calculate your due date if you know when conception occurred. Gain clarity on your pregnancy timeline and prepare for your baby’s arrival.
Many expectant mothers wonder, "When did I conceive?" or "What day did I get pregnant?" Typically, gestational age—the age of the baby—is measured from the first day of the mother’s last menstrual period (LMP). However, conception doesn’t occur until ovulation and fertilization, which usually happens at least 10-14 days after the LMP. This calculator estimates your conception date and provides a possible range of days when intercourse may have led to conception, accounting for various factors.
Last Menstrual Period (LMP): Conception typically occurs 11-21 days after the first day of your LMP in women with regular cycles. This method estimates conception by adjusting for your cycle length, though it’s less precise for irregular cycles or if you don’t recall your LMP. In such cases, an ultrasound may provide a more accurate estimate.
Due Date: If you know your due date (often provided by a healthcare provider during a prenatal visit), this method calculates conception by subtracting 266 days, the average time from conception to birth.
Ultrasound: An obstetric ultrasound uses sound waves to create images of the fetus, helping measure its size and estimate gestational age. This is especially accurate in early pregnancy (5-6 weeks after LMP) and can refine conception estimates when combined with LMP data.
Known Conception Date: If you know your conception date, this method adds 266 days to estimate your due date, providing a straightforward timeline.
Fertilization occurs when a sperm and egg unite in the fallopian tube, forming a fertilized egg that begins developing into an embryo. Conception, however, involves both fertilization and implantation of the embryo into the uterine wall. Medically, a woman is considered pregnant only after implantation. This distinction is important, as some definitions (e.g., in U.S. state laws) may vary, but the medical consensus aligns with implantation as the start of pregnancy.
Pinpointing conception is challenging due to factors like irregular ovulation, sperm survival (up to 5 days in the body), and variations in implantation timing (6-12 days after fertilization). Stress, health conditions, or lifestyle factors can also shift ovulation. Early ultrasounds and ovulation tracking (e.g., using basal body temperature or ovulation predictor kits) can improve accuracy. Always consult your healthcare provider for a personalized timeline.
It’s an estimate based on average ovulation timing. Actual conception can vary due to cycle length, ovulation timing, or other factors.
Yes, but the estimate may be less accurate. Enter your average cycle length, and consider using the ultrasound method for better precision.
You can use your due date, ultrasound results, or a known conception date instead. An ultrasound can also help determine your pregnancy timeline.
No, day 14 is an average for a 28-day cycle. Ovulation can occur earlier or later depending on your cycle length.
Ultrasound measures fetal size to estimate gestational age, which is more accurate in early pregnancy. It can confirm or adjust estimates based on LMP.
Built by xAI, this Pregnancy Conception Calculator uses standard medical guidelines to help you understand your pregnancy timeline. It’s designed to be simple and informative, but for precise details, always consult your healthcare provider.