How many days after missed period does implantation occur

Implantation bleeding is light bleeding that may happen about six to 12 days after conception. It may be caused by a fertilized egg implanting in the blood-rich lining of your uterus. Implantation bleeding can be an early sign of pregnancy, but some women mistake it for menstrual blood because it may happen around the time they expect their period.

Implantation bleeding

Implantation bleeding is light bleeding that a small percentage of pregnant women have at about six to 12 days after fertilization. Here's the theory behind why it happens:

After the sperm fertilizes the egg, it starts the three- or four-day trip from the fallopian tube to your uterus. During this time, it divides into hundreds of identical cells. Meanwhile, your ovaries release estrogen that causes the lining of the uterus (the endometrium) to thicken and develop more blood vessels. The uterine lining is preparing to host the quickly growing egg that will soon become an embryo.

Once the egg enters the uterus, it's called a blastocyst, a tiny ball of several hundred cells. A day or two later, it begins burrowing into the blood-rich lining of your uterus, where it continues to grow and divide. As it burrows into the endometrium, the blastocyst may cause little blood vessels to burst, resulting in a small amount of vaginal bleeding.

Implantation bleeding symptoms

In addition to light bleeding, some women also have these other implantation symptoms:

  • Light cramping (less than with a normal period)
  • Nausea
  • Breast tenderness
  • Lower back pain
  • Mood swings
  • Headaches

Note that these symptoms are no guarantee that you're pregnant – they can also be signs of ovulation or PMS. Taking a home pregnancy test is the best way to find out if you're pregnant. (Though you may have to wait a few more days to get an accurate result.)

If you do get your period instead of a positive pregnancy test, and haven't yet scheduled a preconception visit with a midwife or doctor, now is a good time to do so.

When does implantation bleeding occur?

Implantation bleeding tends to occur during the week before you would expect your period, or about six to 12 days after conception. This is around the same time a fertilized egg would be attaching itself to the uterine lining.

How long does implantation bleeding last?

Unlike a regular menstrual period, implantation bleeding usually lasts no more than a day or two. This is the amount of time it takes for the fertilized egg to become implanted into the lining of the uterus.

How common is implantation bleeding?

By some estimates, about 15 to 25 percent of women experience implantation bleeding. Some women may think they’re having a light period when they see the spotting. They may not realize they're pregnant.

How can I tell if it's implantation bleeding or my period?

Here's how to tell whether your bleeding is more likely to be implantation bleeding or your period:

  • Amount of blood. Implantation bleeding is a lot lighter than a typical period. It's usually just a little spotting.
  • Length of time. Most women bleed for three to seven days during their period. Implantation bleeding often lasts only one to three days.
  • Color. Menstrual blood is usually bright red or dark red, but implantation bleeding tends to be a light pink, brown, or rust discharge.
  • Clotting. Many women bleed enough during their period that some of the blood clots or becomes like a gel. Implantation bleeding is too light to clot.

When to see a doctor for bleeding in early pregnancy

If you continue spotting even after a positive pregnancy test, or if you develop other symptoms (such as pelvic or abdominal pain, dizziness, or lightheadedness), call your provider immediately.

You may need an exam to make sure you don't have an ectopic pregnancy. This happens when the fertilized egg grows outside the uterus, usually in a fallopian tube. (It's possible to have an ectopic pregnancy even if you don't get a positive result on a pregnancy test.)

Bleeding or cramping in early pregnancy may also be a sign of an impending miscarriage. But many women spot in the first trimester for no apparent reason and go on to have a completely normal pregnancy.

Learn more:

Quiz: Am I pregnant?

Video: What is implantation bleeding?

If you think you may have conceived this cycle, you might be looking for an implantation calculator. These little tools were developed to estimate when the fertilized egg may have burrowed into your uterine lining, thereby beginning your pregnancy. You’ll find a plethora of these nifty little calculators online promising to tell you your implantation date. But the reality is, they can’t.

Before getting into the details on why these calculators aren’t very accurate, here’s how they work. Implantation most often occurs 9 days after ovulation. Based on this information, there are two common ways to estimate when implantation occurs for you.

  1. If you know the date you ovulated, add 9 days.
Ovulation date + 9 days =  Implantation date
  1. If you know the first day of your last menstrual period (LMP), add 23* days.
Date of last menstrual period + 23 days =  Implantation date

*23 days =  14 (average number of days between LMP and ovulation ) + 9 (average number of days between ovulation and implantation)

Important note: The above calculations are a very oversimplified guess. The reality is that your cycle is variable and the day you ovulate won’t necessarily be consistent from cycle to cycle.

So while using averages like 14 days (between LMP and ovulation) and 9 days (between ovulation and implantation) will tell you when implantation tends to happen on average for women as a whole, it won’t tell you much about when implantation happened for you.

What is implantation?

Implantation is the process of an embryo attaching to the uterine lining. This attachment to the uterine lining is what allows the embryo to receive oxygen and nutrients from the mother, and continue to progress and grow into a fetus.

As soon as implantation is complete, the embryo begins to produce the hormone hCG. This is the hormone that turns a pregnancy test positive.

HCG plays an important role in early pregnancy. When you are not pregnant, a drop in the hormone progesterone is what causes your period to begin (progesterone is the hormone that maintains the uterine lining). But the presence of hCG sends a signal for progesterone production to continue, and your uterine lining is maintained throughout your pregnancy.

What does implantation mean for pregnancy?

When you’re trying to get pregnant, “When did I conceive?” is a pretty common question. However, a better question might be, “When did implantation occur?”

Many people assume that pregnancy begins at conception—the moment that sperm enters the egg. 

A more accurate beginning of pregnancy would be the implantation date rather than the conception date. Implantation, or the process of the combined egg and sperm cells attaching to the wall of the uterus, marks the actual start of a viable pregnancy.

According to recent research published in Nature Biotechnology, conception occurs much more readily than implantation, but this does not ensure pregnancy. For the pregnancy to be viable, the cells must make contact with the endometrium and attach to the uterine wall.

As many as two thirds of embryos fail to implant. This indicates that embryos are likely predestined for survival or death before even the first cell division.

If progesterone hasn’t adequately prepared the endometrial lining to support life, or if the blastocyst contains abnormalities, implantation will fail. When this happens, the egg dies and is excreted during your next period.

When does implantation occur?

In most successful pregnancies, implantation occurs 8 – 10  DPO (days after ovulation). The most common day is 9 DPO.

While it’s possible for implantation to occur between 6 – 12 days after ovulation, implantation earlier than 8 days after ovulation is rare.

Can you have late implantation?

According to a study published in the New England Journal of Medicine, the estimated risk of early loss is strongly related to the time of implantation. The study found that early loss was least likely when implantation occurred by the 9th day past ovulation (DPO) and the risk increased with each successive day—most substantially after day 11*.

Here are the specific results:

Implantation Date (in Days Past Ovulation) Risk of early pregnancy loss
9 DPO 13%
10 DPO 26%
11 DPO 53%
after 11 DPO 82%

If implantation occurs later, it is more likely to result in early loss or a chemical pregnancy (chemical pregnancy is the term given to a miscarriage that occurs before the fifth week of gestation, and early loss is a miscarriage that happens in the first six weeks of gestation.).

While it’s not fully understood why later implantation tends to result in early pregnancy loss, researchers speculate that embryos that are slow to implant must be impaired in some way. 

When did implantation occur for me?

Based on your knowledge of your last menstrual period or ovulation date, you can estimate when implantation might have taken place. (This is why tracking your cycle is incredibly valuable, as it can help you find out when ovulation occurs for your body, specifically.)

If you have a pretty good idea of when ovulation happened, then you can estimate that implantation most likely happened  8 – 10 days past ovulation (DPO). 

How long does implantation last?

Most of the time, implantation follows a relatively stable timeline. Sperm can live for about five days, waiting for an egg’s release. Once an egg is released from the ovary, it begins a journey down the fallopian tubes and must be fertilized within 24 hours.

If a sperm does fertilize the egg, and the resulting blastocyst makes it to the uterus, it can still take several days to implant itself in the uterine wall. In all, the entire process usually takes 8 – 10 days, though, in some rare cases, implantation may occur as early as the sixth day, or as late as 12 days, after ovulation.  

What are the signs and symptoms of implantation?

Many women wonder when they can start expecting signs and symptoms confirming their hoped-for pregnancy. Who hasn’t Googled “early pregnancy symptoms” 24 hours after sex?

However, implantation symptoms are a debunked myth. Even though many sources use the word “burrowing,” which certainly sounds like it should feel like something, implantation involves only a few cells and causes no unique pain or cramping.

In fact, the cramping people often associate with implantation cramps results from the high levels of progesterone already present during the luteal phase of your menstrual cycle.

If you’re wondering what implantation feels like, remember that the embryo is about half the size of a dust mite—not large enough to cause cramping, pain, or other physical sensations.

How about implantation bleeding? People talk about that all the time, right? Sorry, this one’s a myth, too. One study found that while 9% of women did experience light bleeding or spotting during early pregnancy, it was rarely on the day of implantation.

Essentially, in the very early days of pregnancy, it’s nearly impossible to differentiate between the signs of an impending period and the signs of early pregnancy.

In fact, many of the symptoms often attributed to implantation can be explained by other causes:

  • Bleeding or spotting: spotting during pregnancy an occur for a variety of reasons, and it is often benign. However, there is no evidence that implantation causes bleeding.
  • Cramping: the hormone progesterone is high during the implantation window. Progesterone slows down digestion and can cause bloating, cramping, and general abdominal discomfort.
  • Pain: Many factors unrelated to pregnancy can cause abdominal pain, and when you’re trying to get pregnant, you’re paying closer attention to physical sensations. This can lead to mistakenly attributing the source of pain to implantation.

The only true sign that implantation has occurred is the presence of the hormone hCG in blood or urine, which you can detect with a home pregnancy test.

How long after implantation can I get a positive pregnancy test?

When you’ve got your fingers (and toes) crossed hoping for a positive result, there’s probably one insistent question looping through your mind: How soon can you take a pregnancy test?

Home pregnancy tests are most accurate when taken on or after the first day of your missed period, which usually occurs 12 – 14 days after ovulation.

Pregnancy tests detect the presence of a hormone called human chorionic gonadotropin, or hCG, which is unique to pregnancy. Your body doesn’t even begin producing hCG until implantation is finished—most likely 8 – 10 days after conception. Once it does, the hormone doubles roughly every 48 hours.

Not all pregnancy tests are created equal. Here are some of the best pregnancy tests on the market.

How to help implantation

If you want to increase the chances of getting pregnant, is there anything you can do to promote implantation? The likely answer is no. There is little you can do to prevent a healthy embryo from implanting.

That said, there are a few things you can do to help implantation (or at  least things you can avoid so as not to hurt your chances):

  • Avoid taking anti-inflammatories: A study published in the BMJ found an 80% increased risk of early miscarriage with anti-inflammatory use around the time of conception.
  • Avoid hot tubs and saunas: There aren’t any studies investigating the impact of hot tubs and saunas on pregnancy rates. If you want to be on the safe side, you can follow the same advice as pregnant women follow: keep the heat below 103 degrees Fahrenheit) and take breaks every 10 minutes. Warm baths are okay!
  • Consider avoiding intense exercise: A study published in the journal Obstetrics and Gynecology looking at women undergoing IVF found that those who exercised 4 or more hours per week were twice as likely to have implantation failure. Keep in mind that these results may not apply to the general population, and that moderate exercise is good for fertility (and general health!).

What is an implantation dip?

An implantation dip is a decrease in basal body temperature temperature that occurs on a single day during the implantation window (between 6 and 12 days after ovulation). Women who track their cycles using the temperature method will notice that if they become pregnant, temperature will remain elevated. The reason for this is that the hormone progesterone is elevated during pregnancy, and temperature is influenced by progesterone levels.

It’s often said that a brief drop in temperature during the luteal phase is not a sign that your period is coming, but rather caused by the implantation process and therefore a sign of pregnancy.

There are no formal studies investigating implantation dips, but the fertility tracking app Fertility Friend has run an analysis on 117,000 cycles to investigate this phenomenon. The analysis found that the so-called implantation dip is more common in cycles that result in pregnancy: 11% of charts with this pattern did not result in pregnancy, and 23% of charts with this pattern did result in pregnancy.

However, Fertility Friend’s analysis did not produce any evidence that the dip in temperature is caused by implantation. Fertility Friend study found that this type of dip was most likely to occur between 7 and 8 days after ovulation, but implantation most often occurs 9 days after ovulation.

Another explanation for the dip in temperature is that estrogen levels briefly increase during the middle of the luteal phase—often between 7 and 8 days after ovulation (estrogen has a suppressing effect on basal body temperature). It’s possible that cycles resulting in pregnancy are more likely to have stronger luteal phase estrogen surges, which could explain the higher frequency of the implantation dip in conceptive cycles (alternatively, a short luteal phase may carry lower chances for pregnancy).

*Note that studies approximate when implantation occurs based on the first appearance of chorionic gonadotropin in maternal urine.

By Tara Avery | Oct 31, 2018


How many days after missed period does implantation occur

Tara Avery

Tara Avery is a freelance writer and editor currently based out of Vancouver, British Columbia. When she's not traveling the world in search of inspiration, she's writing fiction, film, and non-fiction across a variety of genres.

How many days after missed period does implantation bleeding occur?

It typically occurs about 10 to 14 days after conception. Implantation bleeding is common, and it usually isn't a sign of a problem. Implantation bleeding is thought to happen when the fertilized egg attaches to the lining of the uterus.

How many days late can implantation occur?

In all, the entire process usually takes 8 – 10 days, though, in some rare cases, implantation may occur as early as the sixth day, or as late as 12 days, after ovulation.

Can implantation occur 6 days after missed period?

For more information, visit our medical review board. Implantation is when the fertilized egg attaches to a woman's uterus. Implantation usually occurs 6 to 12 days after conception, or about day 25 of your cycle.

Does implantation start the day of your missed period?

Implantation bleeding and menstrual bleeding don't happen at quite the same time. Implantation bleeding happens a bit earlier than when you would expect to get your period. Let's walk through the timing, so you can compare dates on your calendar. Day 1 of your menstrual cycle is the first day of your last period.