What is Implantation Bleeding? Causes & Symptoms

What is implantation bleeding? How do you distinguish implantation bleeding from your menstrual cycle? What causes it and what are the signs?

What is Implantation Bleeding?

Implantation bleeding typically occurs when a fertilized egg moves to the uterus and embeds itself into the uterine lining. This typically occurs around 6 to 14 days after fertilization. When the egg is on the move it can occasionally get attached to the internal lining of the uterus and result in unanticipated bleeding.

However, it’s important to remember that implantation bleeding only occurs in around a third of women and so is not a common situation. It typically occurs on average at the time of your first missed menstrual period.

This can often result in many women becoming confused as to whether the bleeding is the start of a menstrual cycle or an indication of pregnancy.

There are some important features of implantation bleeding, which can help you differentiate it from other common causes such as menstruation. However, it’s important to get some background information.

What Causes Implantation Bleeding?

Implantation bleeding is the result of a fertilized egg embedding into the uterine wall. This occurs when the egg joins the uterus and your body instinctively attempts to flush it out of your system. One of the main purposes of menstruation is to maintain a healthy, clean and well-functioning uterus.

During the process of menstruation, you are shedding the uterine lining as you have not become pregnant. When you do conceive, your body responds by halting the menstrual cycle, however, since implantation can occur at such an early stage in pregnancy, your body may still be functioning as usual, which can be misleading.

If you do not experience implantation bleeding, this is not a cause for concern, since, as previously mentioned, only a minority of women actually experience implantation bleeding.

It is thought that this can occur in some cases when fertilization occurs within such a small window to your regular cycle that your body naturally wants to begin menstruation.

What is the Difference Between Implantation Bleeding and Menstruation?

Menstrual bleeding is the stage in your menstrual cycle when your body expels the uterine lining. This process typically takes anywhere from 2 to 7 days and can differ between women, from exceptionally heavy bleeding to extremely light, which can be dependent on the individual concerned and diet.

Implantation bleeding is sometimes compared to spotting. It isn’t a heavy, incessant stream like menstruation, but instead appears as a small number of blood spots, spread throughout a 24 hour period or up to a few days. There are a number of other differences you can watch out for too, these include:


The majority of women are familiar with the color of their menstrual blood. Typically, periods are bright red and only fade to a brown hue towards the end of the cycle. However, implantation bleeding will often be light pink in color and even in some cases brown from the start and it often doesn’t last as long as a period.


Often women report the presence of small clumps, which is an indication of clotting during menstruation. This is relatively common during menstruation, but should not be present during implantation bleeding. If you have a confirmed pregnancy and are seeing visible blood clumps you should visit your nearest emergency room as soon as possible as this could be a sign of a miscarriage.


As mentioned, menstruation usually lasts from 2 to 7 days. However, if you are experiencing implantation bleeding, this will usually last for a much shorter period of time, perhaps as long as 3 days.


Each woman has variations in their periods and no two are ever the same. Some women have extremely heavy periods that last for just a few days, while others bleed light for as long as a week, while other can bleed heavily for 6 days! However, implantation bleeding, which can vary, is usually only a light amount.

The majority of women only experience as a result of implantation bleeding, although, for some women light bleeding can occur instead of simply spotting.

What Are The Signs?

Some signs of implantation bleeding are as follows:

  • Light cramping – much easier to bear than premenstrual cramps.
  • Mood swings – this is not always a telltale sign considering some women experience mood swings during pre-menstruation as well.
  • Headaches – these are common in first trimester pregnancies around the time of implantation.
  • Nausea – this can indicate ‘morning sickness’, which can happen at any time of the day.
  • Breast tenderness – this is from the rush of hormones. This can also be fuzzy since some women experience breast tenderness before their period.
  • Lower Backache – Some women experience lower back pain during implantation.

Other Early Pregnancy Symptoms

Other early pregnancy symptoms include:

  • Food cravings
  • Sensitivity to smells and/or light
  • Fatigue
  • Frequent urination


  • Constipation

Other Causes of Bleeding During Pregnancy

There are other causes of bleeding during pregnancy besides implantation bleeding. Some of these include:

  • Sex – When a pregnant woman experiences intercourse, especially early on in her pregnancy, she may bleed slightly. This is not a heavy flow and should stop on its own. Though this is most common during the first trimester of pregnancy, it may happen at any time. This is thought to be due to hormone changes in your body.
  • Ectopic pregnancy – An ectopic pregnancy, or ‘tubal pregnancy’, is where the egg does not finish its journey to the uterus and embeds itself in the fallopian tubes instead. You may experience bleeding, heavier than implantation bleeding, and severe cramps. This can potentially be life-threatening and you will need to see a doctor as soon as possible. Another common symptom of ectopic pregnancy is a feeling that you’re ‘not pregnant’.
  • Miscarriage – This is what most women, first-time moms especially, fear when implantation bleeding occurs. Miscarriages consist of heavier bleeding, accompanied by what looks like blood clots, and severe cramps. Roughly 15% of pregnancies end within the first few months. If you have heavy bleeding, clotting, and severe cramps and know that you are pregnant, go to your nearest emergency room or schedule an appointment with your doctor.

How to Tell When It’s All Over

A lot of women want to be able to tell if their implantation was a victory. The fertilization process lasts about 7-10 days. If the process of fertilization is unsuccessful, the egg will be released by light-bleeding accompanied by small blood clots.

If the process is prosperous, you will experience implantation bleeding and slight cramping for up to a week afterward. Don’t worry, this is due to successful fertilization and the cramping is perfectly normal, as long as it doesn’t rise above a slight ache.

Your uterus will also change in size and shape, which should be able to be felt through your stomach, right above your pubic bone. It will feel like a small balloon inserted into your pelvic cavity.

When to See a Doctor

As with everything, there are times where it’s better to be safe than sorry. If your bleeding is heavy, lasts longer than three days, or is accompanied by clots or severe cramping, it’s time to see your physician. These may be signs of a serious complication or miscarriage, which are dangerous for you and your baby.

Need More Confirmation?

If you aren’t sure if you are experiencing your normal menstrual period or if it’s implantation bleeding, or you think that you may pregnant and are worried about the implantation bleeding.

Schedule an appointment with your doctor, get some advice which will calm your nerves and ensure that everything with you and baby is okay. Like many pregnancy symptoms, such as Montgomery tubercles it can often be misleading.

If you aren’t sure if you’re pregnant or not, take an at-home pregnancy test to confirm the pregnancy and schedule an appointment with your doctor. Many women find positive ovulation tests to be extremely helpful when it comes to planning their pregnancy.

Leave a Comment