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Implantation Calculator – When Does Implantation Occur? How To Use This Calculator ?
It is simple. And it depends on the way you are trying to conceive – natural or through fertility treatment. If it is a natural way, enter the first day of your last menstrual period and the average cycle length. It would be even better if you know your ovulation date. If you have undergone a fertility treatment, you should pick your embryo transfer date. Once you give these details, you will get the dates, which are important for you to know about conception.>

Implantation is the initial phase of pregnancy when a fertilized egg adheres to the uterine wall. It is most likely to happen around nine days post ovulation but can range from six to 12 days. Here is one such calculator that shows the possible implantation dates based on when you have ovulated or when your last menstrual period was. This is when the pregnancy hormone doubles quickly and lets you know when to take a pregnancy test that comes positive.

When Does Implantation Most Likely To Occur

implantation calculator for pregnancy

Implantation is a critical step in the conception process. It is the time when the embryo adheres to the uterine wall. You may see light spotting or bleeding after implantation and that is one good sign for you to note the time of implantation.

Implantation period is very short, and therefore the sperm needs to be ready to meet the egg. If the sperm is too early or late, it cannot form an embryo.

Ovulation, which is the release of eggs, typically happens around 12 to 14 days after the first day of a period (or the start of a new cycle). Implantation occurs 6 to 12 days post ovulation.

Calculating the ovulation dates, menstrual cycle and implantation can be very confusing. This is where an implantation calculator will help you. This calculator also helps you understand that the bleeding you have spotted is not because of a miscarriage or your next period, but due to implantation.

Difference Between Implantation Bleeding and Menstrual Period

Implantation Bleeding vs Menstrual Period

Implantation Bleeding occurs around seven to 14 days past ovulation (DPO) when the fertilized egg is implanted in the lining of uterus wall. While it’s happening, a small part of uterine lining can be released or disturbed, resulting in bleeding. Implantation Bleeding or spotting is usually pink or dark brown in color. Whereas period blood tends to be bright and vibrant red. During implantation, the blood takes time to travel from the uterine wall to the vagina, and thus it changes color from red to dark brown or pinkish as it is no longer fresh. Implantation bleeding is lesser. At times, the bleeding could just be a single spot, on go for few hours or up to 1 - 2 days. But, if bleeding starts lighter and gets heavier later with constant flow and continues for 4 to 7 days then it is certainly your menstrual period.

Implantation bleeding occurs about 10 days past ovulation. So, if you find pinkish or dark brown spotting on the 22-25th day from your LMP that this could be implantation bleeding. While menstruation generally occurs 14 days past ovulation i.e around 26-27th day from LMP. During Implantation bleeding, a woman can experience light and low strength abdominal cramps whereas menstrual cramps are more intense and stronger.

Most Frequently Asked Questions About Implantation

Q. What does implantation cramping feel like?

Cramping is also a sign of implantation. Most women tend to confuse implantation cramping with menstrual cramping. But the major difference is that former is milder and lasts longer. The cramping is usually felt in the lower back because of the regular series of contractions that the walls of the womb undergo.

Q. How long does implantation cramping last?

Implantation cramping can last over one or two days.

Q. How common is implantation cramping?

Implantation cramping is quite common at that stage, but varies from one woman to another. There are also chances of it not occurring at all during the process.

Q. When can you take a pregnancy test?

The level of hCG hormone has to be more than 25 mlU/ml for the pregnancy to be detected. If the level is lower than this, the pregnancy cannot be detected, even after implantation. Therefore, you must wait at least a week or two after missing the period to take the pregnancy test.

If you experience these signs and have a delayed period, it’s likely that you are pregnant. To get the exact results, take a home pregnancy test. It will give you accurate results. If you get negative results, wait for at least three days before you do the test again.

You can even get a blood test done to see if you are pregnant. Blood tests are more accurate than home pregnancy tests. These tests will give you accurate results as early as 6 days after ovulation.


Remember, the implantation calculator is one of the many ways to determine pregnancy, not the only one. If you have any concerns regarding pregnancy or implantation or if any of these symptoms persist, contact a gynecologist.

Do you have any questions regarding the implantation calculator or any other related topics? Tell us in the comment section below!

  • Melli

    I started on 4/6 and it lasted till 4/13 like normal menstrual. Then on 4/27 I started again but only when I went to urinate I was only bleeding. I wore a pad but nothing came out, only when I went to the restroom it happen. At first it was brown blood for the first couples of days, then went to a dark red. Now I’m waiting to start again. Is this an implantation or I was on mine menstrual cycle?

    • MomJunction


      It’s hard to say whether it’s implantation bleeding or menstrual bleeding without knowing the symptoms.
      Please take the home pregnancy test to confirm whether you are pregnant or not.

  • MomJunction

    Congratulations Sara!
    We are glad that you were able to calculate the day of your implantation using our calculator.
    You can go through our other pregnancy articles too which are informative.
    Happy pregnancy to you. Take care!

  • MomJunction

    That’s great!
    Tell us the good news soon.

    • CarmenV

      As of today im 2 days late and i still haven’t took a pt yet…kinda nervous because besides my missed period and my nausea and fatigue im not experiencing any other signs of being pregnant i dont wanna be pregnant but i feel as though i will be disappointed if it comes back negative…i will take it tomorrow…

    • CarmenV

      So i am 2 days late and still haven’t took a pt yet nervous cause im not experiencing no other symptoms except missed period nausea and fatigue…my breast arent sore and i do not have to pee alot…should i even be takin a pt…possibly something else wrong…never missed a period before though

      • MomJunction

        Hi Carmen,

        You could wait for a week, if you still don’t get your period, then take the pregnancy test. The HCG (pregnancy hormone) levels should increase considerably to detect your pregnancy. Sometimes the levels can be too low and that can give you a negative test result.
        Take Care!

  • momjunction


    Your ovulation date is 20 Aug 17.

  • momjunction


    Missed periods can also occur due to stress, weight gain, thyroid irregularity or PCOS. So, wait for a week and then go for a home pregnancy test.

  • momjunction


    Your ovulation date is 23 August 2017.

  • momjunction

    Hi Theresa,
    If the bleeding is for one or two days, it would be implantation bleeding. But if it continues for more days, it can be your menstrual period. But it you are experiencing lighter and low strength cramps, it is always better to take a home pregnancy test. You can take it on any day from now.

  • momjunction

    Hi syeda maham zahara,

    You can know your ovulation date from the ovulation calculator.

  • momjunction


    Your safe period is between Nov 13 2017 -Nov 21 2017 .

  • momjunction


    Please take a home pregnancy test to confirm it.

  • momjunction

    Hi Lisa,

    Since you already got a positive pregnancy test, your date of conception would have been on the day you had an intercourse or some days later since sperm can live up to five days. Since egg lives for 24 hours, if you had intercourse on Aug 09, you might have also conceived on the same day.

  • momjunction

    Hi Besame,

    If you are experiencing pregnancy symptoms such as constant bloating feeling, nausea then go for a blood test. Blood tests will give you precise results soon after 6 to 8 days of ovulation.

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