A pregnancy calculator just requires inputting the date of your last menstrual period. You will also need to input the number of days in your menstrual period. If you have irregular periods you might have a problem using a pregnancy calculator so it may be best to see if your doctor can give you some guidelines. If your periods are regular, then you can go ahead and input the required dates in the pregnancy calculator to find out:
- Determine the due date
- Calculate the likely conception date
- Calculate the end of the first and second trimesters
- Find out for how many weeks have you been pregnant
- The due date or EDD, estimated date of delivery (remember this date is only approximate, although your pregnancy calculator will pin point an exact date, it is unlikely that your baby will be born on that day).
A menstrual cycle lasts approximately 28 days. This number can vary hugely, but you will need to know it to use the pregnancy calculator. An ultrasound can help you determine fetal age (which is not the same as the length of time you have been pregnant). Ultrasound measurements are accurate at determining gestational age but these require appointments and specialists. Online pregnancy calculators are more convenient to calculate dues dates or time of conception.