Conception Date Calculator

Find out when your little one was conceived

If you want to know when your baby was conceived, you'll do well by engaging the services of a conception date calculator.

How a Conception Date Calculator Works

A calculator of this type takes the first day of your last menstrual period along with the average length of your cycles and deduces the following:

  • Estimated due date
  • Estimated date of conception
  • How far along in your pregnancy you are
  • Estimated fertility window

In addition, some women try to use a calculator to predict or influence the gender of their baby based on when they had (or plan to have) intercourse relative to the ovulation date.

Finding a Calculator

Pregnancy and Baby has a conception date calculator that allows you to enter date of the first day of your last menstrual period. From that, it will give you the likely conception date for a 25-38 day cycle. If your doctor assumes a 28 day cycle, the due date you're given at your appointment could be a few days off if you have a longer or shorter cycle. To use this calculator, you'll need a Java-enabled browser.

American Pregnancy has one that asks for the date of your last menstrual period and the average length of your cycle. Clicking on the Calculate! button gives you your estimated fertility window, estimated conception date, estimated gestational age (which is how far along you are in your pregnancy), and your estimated due date.

Health Link takes the regular menstrual cycle information and gives you an estimated conception date, the date of when your first and second trimesters will end, and an estimated due date. For even further information, it offers an option where you can input a specific date in the future and find out how far along you'll be. This calculator allows you to calculate backwards, too, so if you have an estimated due date, you can find out your conception date and the date of your last period.

Baby Med isn't ideal for those who really want specific information, but for a quick glance at your cycle and your pregnancy, you can enter in your due date. From that date, the program counts backwards to arrive at a window of time when you were likely to conceive. It is roughly a five-day window.

Uses for Calculators

There's more than one use for a conception date calculator. You can also use them to determine the due date, but you mmight also tip the odds in your favor if you prefer a boy or a girl.

Determining Due Date

True to its name, a calculator of this sort will, in fact, assist you in estimating your due date based on your conception date. That means you get out of doing the math! Similarly, you'll be able to gauge how far along in your pregnancy you are.

If you already know your due date but you want to know when you conceived, some calculators will even count backwards. To get your due date without knowing exactly when you conceived, your doctor can do a blood test for an estimate.

Influencing the Gender of the Baby

Male sperm race toward the egg faster than female sperm, but they die more quickly. If you stop having intercourse three days before you're due to ovulate, your chances of conceiving a girl are greater. Hoping for a boy? Have sex one to two days before ovulation. This is definitely not a guarantee, but you do raise your odds for conceiving the gender you're wishing for.

When They May Not Work

To use a conception calculator, you'll need to have fairly regular periods in order to get the most accurate results. If you don't, you may want to track your fertility for better results. If your cycles don't come at regular intervals, you will be missing key information when it comes to using a conception calculator.

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