What you need to know about implantation bleeding

What you need to know about implantation bleeding

A little spotting early in pregnancy doesn’t necessarily mean there is a problem. Implantation bleeding is a common early pregnancy symptom, and it just means your fertilised egg has implanted in the womb. However, if you see blood and are in any way concerned, it’s best to get it checked out by your healthcare professional to rule out anything serious. If you want to know more about implantation bleeding, what it is, what it looks like, and when it happens, then read on.

What is implantation bleeding?

Implantation bleeding is the light spotting or tiny bit of bleeding that sometimes happens after an egg gets fertilised and the fertilised egg attaches to the lining of the uterus where it implants into the womb to grow. When implantation occurs, it can break some of the blood vessels in the uterine lining. However, not everyone will get implantation bleeding.

Why does implantation bleeding happen?

Around the time you are fertile and release an egg, the lining of your uterus is filled with blood vessels and vascular tissue - a perfect environment to increase the chances of achieving a successful pregnancy. If you don’t get pregnant, this lining breaks down and causes your menstrual period. However, when an egg is fertilised, it needs to embed into this lining so the embryo can grow. This process can cause some of the blood vessels to break and release a little bit of blood. Once the fertilised egg attaches to the uterus, the uterus lining remains thick, which allows the pregnancy to continue.

When does implantation bleeding occur?

Although the exact time will vary, implantation bleeding usually happens 7 to 9 days after the egg is fertilised. The fact that it can occur around the time you’d normally get your period, it’s often missed or mistaken for a light and short period. 

What does implantation bleeding look like?

When you have implantation bleeding, you’ll most likely see light spotting, only a few drops of blood, on your underwear that can be brown or light pink in colour. Unlike menstrual bleeding, you won’t see any clots, and it will last for a very short period of time.1

If you are concerned with any form of bleeding, in any colour, during early pregnancy always consult a healthcare professional. 
 

How can I tell the difference between implantation bleeding and my period?

The main difference is the amount of blood you see and the colour. Implantation bleeding is often very light, it should not soak through a sanitary towel or underwear2 and you shouldn’t feel any heavy cramping with it. However, if you do feel cramping, it will likely be very mild.3 Consult your healthcare professional if you have heavy bleeding or any other concerns.

 

Infographic comparing the signs and symptoms to tell the difference of implantation bleeding and your period

What are the signs and symptoms of implantation bleeding?

You may experience a few drops of blood and light cramps for a day or so around the time of implantation – you may not even know you are pregnant when this happens. Then again, it is also common to have none of these.  However, it is also perfectly normal to not experience either of these symptoms.  Implantation bleeding is just one of the early signs of pregnancy. Other symptoms you might also notice are1,4

  • nausea
  • fatigue
  • tender breasts
  • frequent urination
  • cravings or aversions
  • bloating
  • mood swings
  • backache in the lower back
  • of course, often the most common sign of a pregnancy is missing your period
     

How much bleeding is safe during implantation?

Most of the time implantation bleeding doesn’t signal a problem. However, if you do notice any blood and are concerned, see a doctor as there is no way to know how much bleeding is safe if you’re pregnant.

When should I worry about bleeding during implantation?

Implantation bleeding itself is not a risk. You should only see very light bleeding and only last a day or two, and it doesn’t come with any pain (some light cramping, at most). However, if you notice bleeding that is heavier than what we’ve described above (and you are pregnant or think you might be), it could point to another condition like an ectopic pregnancy (when an embryo starts to develop outside of the uterus, typically in a fallopian tube), so see a healthcare professional right away.

How long does implantation bleeding last and how heavy is the bleeding?

The few drops of blood you might get with implantation bleeding may only last a few hours, though it can last a few days. It can vary from person to person, but it’s rare for it to last for longer than three days. 

Should the bleeding last longer, or if it is heavy in any way for example, you are filling up pads then it’s unlikely that what you’re experiencing is implantation bleeding. It could be ‘just’ your period, and a pregnancy test will help clarify.  Always see your healthcare profession if you are concerned.   

How long after implantation bleeding can I take a pregnancy test?

As implantation bleeding occurs around the time you would expect your period, you can take a home pregnancy test right away, as long as it’s one designed for ‘early testing’, i.e., up to 5 days before your period is due (6 days before a missed period). Though ultra-sensitive to tiny amounts of the pregnancy hormone, if you test very early these tests can give you a negative result even if you later find out you are pregnant, as the amount of hCG may be too low to detect yet. If you see a negative result, but still think you are pregnant, wait 3 days before testing again. HCG levels rise rapidly in early pregnancy, so you’ll soon be able to see a positive result if you are pregnant.

Does every woman get implantation bleeding?

No. Bleeding occurs in 15% to 25% of early pregnancies5. In most cases, spotting is a normal sign of implantation, but any bleeding should be checked out if you’re worried, because it could still be a symptom of a miscarriage or an ectopic pregnancy.

Implantation bleeding is usually nothing to worry about. You may not even know you’re pregnant when you notice it. If you see any spotting around the date that you would normally start your period, and you suspect you are pregnant – take a pregnancy test. If you get a positive pregnancy test, talk to your doctor or healthcare professional and mention any bleeding you have, just so any other factors can be ruled out. 

Implantation bleeding concerns

Implantation bleeding itself is not a cause for concern, nor is the developing baby at risk. However, vaginal bleeding of any kind could be another condition that does require medical attention. 

Any bleeding you notice after a missed period (whether you already confirmed you are pregnant or not) is not normal and should be checked out by a medical professional. There are several possible reasons why it may occur, like:

  • Cervical irritation, for example, following a gynaecological exam.
  • Irritation or tears following intercourse
  • After excessive exercise, exertion, or heavy lifting
  • A vaginal infection.

Resources

  1. American Pregnancy Association. “What Is Implantation Bleeding?,” September 20, 2023. https://americanpregnancy.org/pregnancy-symptoms/what-is-implantation-bleeding/.
  2. “Bleeding in Pregnancy,” n.d. https://www.tommys.org/pregnancy-information/pregnancy-symptom-checker/bleeding-pregnancy.
  3. Smith, Lydia. “What Is the Difference between Implantation Bleeding and a Period?” Patient, January 18, 2022. https://patient.info/news-and-features/what-is-the-difference-between-implantation-bleeding-and-a-period.
  4. Professional, Cleveland Clinic Medical. “Implantation Bleeding.” Cleveland Clinic, n.d. https://my.clevelandclinic.org/health/symptoms/24536-implantation-bleeding.
  5. Snell, B. J. (2009). Assessment and Management of Bleeding in the First Trimester of Pregnancy. Journal of Midwifery & Women's Health, 54(6), 483-491. https://doi.org/10.1016/j.jmwh.2009.08.007