The babyMed pregnancy calendar gives you personalized details on what is happening to you and your and baby. It is based on a typical 40-week pregnancy and displayed in a week-by-week format. Just enter your due date above to create your pregnancy calendar.
The calculation of the pregnancy due date is the single most important part of prenatal care. Everything in pregnancy depends on what your exact due date is and how many weeks along the pregnancy has come. Decisions to treat, test, and deliver depend on knowing the exact due date.
When can you find out your due date?
Determining the due date is done best early in pregnancy. A sonogram done before 12 weeks can estimate the due date within 5-7 days, between 12 and 20 weeks the range of error is about 2 weeks, and after 20 weeks the range is 3-4 weeks. That is why it is important to make a clear determination of the exact due date as early as possible in pregnancy.
In order of accuracy, here are the ways to determine the pregnancy due date:
- In-Vitro IVF transfer day (Correct to the due date day)
- Basal body temperature chart (Correct to a few days)
- Ultrasound before 6-8 weeks (Correct to about 5-7 days)
- Ultrasound 8-12 weeks (Correct to about 7-10 days)
- Ultrasound 12-24 weeks (Correct to about 2 weeks)
- Ultrasound after 24 weeks (Correct to between 3-4 weeks)
- Last menstrual period (Correct to within a few weeks)
- Size of the uterus (not that correct)
- First positive pregnancy test (only if there was a negative test within a week before)
- hCG levels (only works before 6,000 mIU/cc and then only within a few weeks of accuracy)
How can I find out my due date?
One important tool to calculate the due date is the babyMed due date calculator, in which you can enter the first day of your last menstrual cycle and other information. Using a due date calculator is just one of many ways to determine the exact due date. The due date calculator will display the estimated date of ovulation and the expected due date of your baby. This estimate is based on the last menstrual period and the estimated date of conception.
Your pregnancy due date is calculated by adding 40 weeks (280 days) to the approximate first day of your last menstrual period or 266 days to the day of ovulation. Only 5% of women deliver their babies on their projected due date, so this date is just an estimate and delivery usually happens within 2 weeks before or after the due date.