Pregnancy Calculator Week by Week | Due Date Calculator - Her Care (2024)

FAQs

How do I calculate exact pregnancy week? ›

To calculate your pregnancy weeks, just count from the first day of your last period to the current date in weeks. That way you will get how many weeks of pregnancy is over. How does the pregnancy due date calculator work? Add 280 days (40 weeks) to the first day of your last menstrual period (assuming a 28-day cycle).

Your due date is 40 weeks after the day you started your last period. This is the most reliable way to calculate your due date on your own at home, but it still isn't perfect.

Your due date is 40 weeks or 280 days from the first day of your LMP, so the number of weeks that have passed since indicate how far along you are. Another method is the 'dating scan'. For this method, your doctor estimates your due date using an ultrasound.

Last Menstrual Period

Conception usually occurs around 11-21 days after the first day of the last period of a woman who has a regular period. The estimation of conception date is based on this, but is rarely ever exact since it is difficult to know exactly when ovulation occurs.

Week 4 of pregnancy

For example, a fertilised egg may have implanted in your womb just 2 weeks ago, but if the first day of your last period was 4 weeks ago, this means you're officially four weeks pregnant! Pregnancy normally lasts from 37 weeks to 42 weeks from the first day of your last period.

If you are counting your baby's age in months, then all you need to do is multiply the months by 4.345 because there are approximately 4.345 weeks in one month. But if you are counting your baby's age in years, then you will multiply the years by 52.176 because there are approximately 52.176 weeks in one year.

This is an estimate based on the woman's menstruation cycle, but some women do not have the standard 28-day cycle; therefore, using the first day of the last menstrual period can still put a due date off by a few days, making it too soon or too late.

Using your last menstrual period date

Therefore, if you know the first day of period, you can add 11 to 21 days to this day to have an idea of when conception occurred. For example, if you are pregnant and your last period started on March 5, that means you likely conceived between March 16 and 26.

You may have simply conceived earlier or later than you thought you did (which can happen if your cycle is at all irregular or if you remembered your last menstrual period date incorrectly). Your doctor might want to repeat the ultrasound to make sure that your pregnancy is developing as it should.

To determine how many weeks pregnant you are, count how many weeks it's been since the first day of your last menstrual period (LMP). For example, if your last period started on April 3 and it's now May 22, then you are 7 weeks pregnant.

Which week is best for delivery? ›

Babies born too early may have more health problems at birth and later in life than babies born later. Being pregnant 39 weeks gives your baby's body all the time it needs to develop. Your baby needs 39 weeks in the womb because: Important organs, like your baby's brain, lungs and liver, need time to develop.

How to Count Weeks in a Month? We can easily count the number of weeks in a month by first counting the number of days in the month. Then, we divide the number of days by 7 since 1 week has 7 days. For example, the month of January has 31 days, so the number of weeks in January would be: 31/7 = 4 weeks + 3 days.

An unborn baby spends around 38 weeks in the womb, but the average length of pregnancy (gestation) is counted as 40 weeks. This is because pregnancy is counted from the first day of the woman's last period, not the date of conception, which generally occurs 2 weeks later.

Many of the signs of pregnancy, such as a missed period (amenorrhoea), nausea (morning sickness) or tiredness can also be caused by stress or illness, so if you think you are pregnant take a home pregnancy test (urine test) or see your GP, who will administer a urine test, blood test or ultrasound scan.

For a woman with a regular period, conception typically occurs about 11-21 days after the first day of the last period. Most women do not know the exact date of conception because it can be challenging to know exactly when ovulation occurs.

If today is January 18, and the first day of your last period was December 5, then we count the days between those two dates, which would be 44 days. This means you are approximately six weeks and two days pregnant. These calculations can be done by hand, using a calendar.

An unborn baby spends around 38 weeks in the womb, but the average length of pregnancy (gestation) is counted as 40 weeks. This is because pregnancy is counted from the first day of the woman's last period, not the date of conception, which generally occurs 2 weeks later.

Once you know the first day of your last period, you can add 11 to 21 days to figure out your conception date. For example, a woman who is due on November 10 can calculate the first day of her last period by subtracting 40 weeks. This means her last period started on February 3.

An ultrasound is actually the most accurate way to date a pregnancy because all fetuses grow at a consistent rate during the first trimester and early second. In other words, if your baby measures 9 weeks 2 days when you have your ultrasound, that's how far along you are, no matter when your last period was.