How To Calculate Last Menstrual Period

What Is Menstrual Period Tracker Know Your Due Period

How to calculate next period date and ovulation time? – Dr. Teena S Thomas

The menstrual period Tracker or calculator takes inputs from user like first day of your last period and the average length of your menstrual cycle to estimate your next due period, Fertile Days ,Ovulation day and Safe Days. MomJunction Period calculator predicts the future periods and ovulation phase for a year so that you may plan for a special event that is period-free.

How Soon Can I Take A Pregnancy Test

A missed menstruation cycle is one of the earliest signs of pregnancy. Thats why we usually recommend waiting until youve missed your period before taking a pregnancy test. You can purchase low cost, high quality pregnancy tests here. If you cant wait that long and you know the day of your last period we can calculate possible conception and your pregnancy due date.

Disclaimer About The Calculator

Our calculator strives for the highest accuracy, but your pregnancy progress may differ from the calculator’s results for several reasons including possible miscalculation errors in input data individual variations in the timing of ovulation, and/or conception.

The information provided regarding pregnancy progress and fetal development is a guide through the weeks. It is not specific information for a specific individual but serves as a general guide only. As each pregnancy differs, any dates, weights, and lengths should be considered general information for interest only.

Our week-by-week guides use both standard and metric units of measure including pounds and kilograms.

Recommended Reading: 90 Probationary Period Employment Form

Example Of A Pregnancy Dating

For instance, in a pregnancy within a cycle of 29 days with the last period starting on February 2nd, 2016 and the current date being May 31st, 2016 the result is:

The probable ovulation date is February 18th, 2016

The fertility window is between February 14th and February 22nd, 2016

The estimated gestational age 16 weeks and 6 days

The estimated due date is November 8th, 2016.

Week 17: To this week your baby is still tiny, measuring about 5.2 inches and weighing almost 5 ounces. Muscular and skeletal development continues. The placenta is continuing to develop in order to offer support to the vital functions of the baby. The placenta is a complex structure with many blood vessels used for feeding the baby with nutriments, providing the necessary oxygen and removing the waste products.

Calculate Your Next Period

How Do I Calculate My Menstrual Cycle?

The menstrual cycle calculator is capable of calculating the dates of your next periods for up to a year. To find out about yours, input the following data about your previous periods:

  • Date that your last period started
  • Duration of the period
  • Average duration between periods

With this information, the calculator can tell you the following:

  • Start and end of your next periods
  • Ovulation period of each cycle
  • Days that ovulation will occur
  • Possible due date if you become pregnant during the ovulation period of that cycle

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How Does The Pregnancy Due Date Calculator Work

  • Add 280 days to the first day of your last menstrual period .
  • Your menstrual period and ovulation are counted as the first two weeks of pregnancy. This is why a pregnancy ovulation calculator is helpful to pinpoint the exact ovulation cycle.
  • If you deliver on your due date, your baby is actually only 38 weeks old, not 40.

Factors Affecting Pregnancy Length

Child’s gestational age at birth is associated with various likely causal maternal non-genetic factors: stress during pregnancy, age, parity, smoking, infection and inflammation, BMI. Also, preexisting maternal medical conditions with genetic component, e.g., diabetes mellitus type 1, systemic lupus erythematosus, anaemia. Parental ancestral background also plays a role in pregnancy duration. Gestational age at birth is on average shortened by various pregnancy aspects: twin pregnancy, prelabor rupture of membranes, pre-eclampsia, eclampsia, intrauterine growth restriction. The ratio between fetal growth rate and uterine size is suspected to partially determine the pregnancy length.

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Why Is Menstrual Period Important To Track

It is important to track menstrual period and the cycle for some reasons. The more you understand about your body and the menstrual cycle, the more quickly you can know if something is amiss. A change in menstrual cycle is often a symptom of a variety of health issues in women.

It is also important to track the menstrual periods if you are planning to conceive or if you are trying to have a safe sex to avoid pregnancy.

The primary goal of tracking your monthly periods is to estimate the length of the menstrual cycle and assume the possible time of ovulation. If you are trying for pregnancy, you can have an intercourse around the ovulation time, and if you want to avoid pregnancy, you should abstain from sex for some days before and after ovulation.

Also when your periods become irregular, it may indicate health conditions such as thyroid issue, hormonal fluctuations, diabetes, liver problems, gaining or losing a significant amount of weight, extreme stress or adopting a new exercise routine. If irregular menstrual periods is coupled with any other symptoms, you should check with your OB-GYN.

Can I Plan My Due Date


Whether you’re trying to avoid being very pregnant in the middle of summer or are a teacher who wants to maximize time off with your little one, you can try to time when you conceive in order to “plan” your due date. But even if you’re one of the lucky ones who’s able to get pregnant when she really wants to, just remember that you probably won’t be able to map out exactly when you’ll give birth to the day .

Still, you can try our Ovulation Calculator, which uses the date of your last menstrual period and your typical cycle length to discover the days you’re most likely to be fertile and increase your chances of conceiving.

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How Far Along Am I

enterdue datelast period

The How Far Along Am I Calculator uses your due date or last menstrual period to calculate how many weeks, months, and days you are pregnant.

different starting dates to count pregnancy

  • Conception or ovulation
  • Measurements from an ultrasound
  • IVF Transfer date

Pregnancy is most commonly measured gestationally from a woman’s last menstrual period to birth. This period is known as gestational aging.

If you require more options to calcuate yourdue date or how far along you are, try ourdue date calulator.

Your Due Date Is Only An Estimate

Please remember that your due date is only an estimate. Every pregnancy is unique and your baby will come when it’s ready. Be sure to talk to your health care provider about your due date.

On average only 5% of births take place exactly on the estimated due date. Most are born within a week either side of the estimated due date. A normal pregnancy can last anywhere between 38 and 42 weeks.

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How To Understand Gestational Age

LMP refers to the first day of your last menstrual period. Health care providers measure pregnancies in weeks starting from the first day of the LMP. If your period is regular and lasts 28 days, and if ovulation generally happens on day 14 of your cycle, then conception probably took place about two weeks after the LMP. For gestational age counting, these two weeks are added to a pregnancy as a simpler method than trying to track from ovulation or fertilization.

Nevertheless, this estimation is not always accurate. It doesn’t take into account factors like changes in the menstrual cycle, variations in ovulation, and imperfect recall by patients.

A due date calendar or calculator can help pregnant people determine their babys due date.

To calculate your due date, add 280 days to the first day of your LMP .

Different calculators can help determine your due date based on ovulation, date of conception, and ultrasound data. Specific calculators can predict the due dates of people who are using assisted reproductive technologies and embryo transfer.

The conception date refers to when a baby was conceived. Since sperm can live inside the vaginal canal for three to five days, conception can take place up to five days after sexual intercourse. Fertilization depends on ovulation and can occur within 12-24 hours from the release of the egg .

How To Use Menstrual Period Calculator

Pin on Printable Free Calendar Templates

It is quite simple 3 step process to calculate your next period and your menstrual cycle using MomJunction period calculator. Also, download customised menstrual calender for year.

  • Enter the first day of your last menstrual period.
  • Enter the average length of the menstrual cycle.
  • Average duration of the last period.

Once you share all the above information,period calculator will share your following menstrual date for a year, fertility calendar, ovulation phase, fertile phase and estimated due date.

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What Is The Last Menstrual Period

The LMP is the date of the first day of the last menstrual period you had before conceiving. It is the first day that your last menstrual cycle begins when you see bright red blood, not just a little brown spotting. You should keep track of your LMP each month, either with an online calculator or just by recording it on a calendar each month. That is the date you use when entering the LMP on an online period calculator.

Whether you are trying to get pregnant or not trying to get pregnant, keeping track of your menstrual periods is vital. Besides pregnancy, missing a menstrual period could also be a sign of other issues like missed ovulation.

Pregnancy Due Date Calculator Guide

  • Enter the date of the first day of your last period
  • Enter the month & year
  • Then hit Calculate
  • The expected date of delivery is calculated by adding one year, subtracting three months, and adding seven days to the first day of a woman’s last menstrual period . The result is approximately 280 days .

    Example: LMP = 20 August 2017

    + 1 year = 20 August 2018

    – 3 months = 20 May 2018

    + 7 days = 27 May 2018

    Please Note : The calculation method above does not always result in a 280 days because not all calendar months are the same length, nor does it account for leap years.

    Childbirth usually occurs about 38 weeks after conception, or about 40 weeks after the last menstrual period. The actual length of pregnancy depends on various factors, for example:

    • The first pregnancy tends to last longer than subsequent pregnancies.
    • Fewer than 10% of births occur on the due date.
    • 50% of births occur within a week of the due date, and almost 90% occur within two weeks of the due date.
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    Dating Pregnancy Using Ultrasound

    Ultrasound in the first trimester is the most accurate method of dating pregnancy. During the scan, baby is measured and the age of pregnancy is estimated by comparing baby’s size against recorded averages. If there is a significant difference between gestational age according to LMP and gestational age according to the ultrasound, you may be given a new gestational age and due date based on the ultrasound measurements.

    Your pregnancy may also be dated by ultrasound measurement if an LMP formula was not appropriate for your pregnancy for any reason. LMP formulas are not suitable in several situations including the following: LMP is not known or is not certain, birth control pills were taken in the two months before LMP, the menstrual cycle is irregular, you are carrying multiples .

    Although the age of pregnancy based on ultrasound measurements is more accurate than the age of pregnancy based on LMP, both are estimates and not definitive statements.

    How Is The Due Date Calculated

    How do you calculate your monthly cycle? – Dr. Phani Madhuri

    The expected date of delivery is calculated by adding one year, subtracting three months, and adding seven days to the first day of a woman’s last menstrual period . The result is approximately 280 days from the LMP.

    Example: LMP = 8 May 2019+ 1 year = 8 May 2020- 3 months = 8 February 2020+ 7 days = 15 February 2020

    The calculation method above does not always result in a 280 days because not all calendar months are the same length, not does it account for leap years. In modern practice, calculators, reference cards, or sliding wheel calculators are used to add 280 days to LMP.

    LMP may not be the best date to use as the basis of a due date calculation, but it remains popular because few women know exactly what day they ovulate or conceive a pregnancy, and because no algorithm can predict the exact day that spontaneous labour will occur no matter what considerations are taken into account.

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    How Long Is Your Menstrual Cycle

    Uh-oh, PMS. Expect the possibility of irritability, cramps and even a few tears right now. Be ready with these 10 tips for tackling PMS and wear your ALWAYS pantiliners too.

    It’s that time again. As the lining of your uterus sheds, your period starts. This is also the official start of your cycle. Want to know more? Here are answers to 10 common period questions. And make sure youre stocked up on ALWAYS pads!

    • Up to 100 % leak-free periods are possible.
    • A better fit means better protection and comfort.
    • Find your size for day and overnight protection.

    Your bleeding has stopped – or at least lightened up a lot by now. Here are more details about the 4 menstrual cycle phases if youd like more details. Because every month is a little different, carry ALWAYS pantiliners with you just in case.

    Drawbacks Of Using Gestational Age

    Due date predictions are not always accurate to some degree, theyre an assumption. Some pregnant people even report their health care providers changed their due dates in the third trimester. In most cases, the due date based on a first-trimester ultrasound is considered the most accurate.

    If the first ultrasound is performed after 22 weeks of gestation, it wont be quite as accurate in estimating the due date. In this case, the pregnancy will not be considered optimally dated.

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    Gestational Age Vs Fetal Age

    Fetal age is separate from gestational age. While the gestational age measures how far a pregnancy has progressed in weeks, fetal age is the growing babys actual age.

    Fetal age is counted from the moment of conception. Thus, it is 14 days less than the gestational age, assuming a regular menstrual cycle of 28 days. Health care providers generally measure fetal age through ultrasounds. An ultrasound lets them measure the size of your baby’s head, abdomen, and thigh bone, which together indicate fetal age.

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