How is the date of conception for a pregnancy calculated?

How do I calculate my pregnancy due date? Your pregnancy due date is calculated by adding 266 days (38 weeks) to your ovulation and fertilization date or 280 days to the first day of your last menstrual period (LMP). Calculating an accurate due date is an important first step in pregnancy. read more

Gestational age, or the age of the baby, is calculated from the first day of the mother’s last menstrual period. Since the exact date of conception is almost never known, the first day of the last menstrual period is used to measure how old the baby is. Use our Pregnancy Calculator to calculate these dates for you. read more

When you calculate due date of pregnancy you can do it by months, trimesters or weeks. The first day is the day do conception. This is the day of ovulation. From that time you have to add 9 months, or 40 weeks to get your due date. read more