Implantation bleeding in pregnancy

When a fertilised egg attaches to the wall of the uterus, some light spotting may occur. This is called implantation bleeding, and it can be one of the earliest clues that you may be pregnant.

Some mums-to-be don’t experience this type of bleeding, and some simply don’t notice it. Read on to find out when implantation bleeding happens and what it looks like.

What Is Implantation Bleeding?

Implantation bleeding is harmless light spotting that can happen after a fertilised egg – by this time called an embryo – embeds itself in the lining of your uterus.

Although it might seem similar to a very light period, it has a very different cause: Implantation spotting is due to tiny blood vessels in your uterus bleeding as the embryo implants itself.

What Does Implantation Bleeding Look Like?

If you have implantation bleeding, the first thing you’ll notice is probably a few streaks or smears of pink or red blood on the toilet paper when you wipe, or maybe some spots on a sanitary pad or your underwear.

Is it Implantation Bleeding or a Period?

It’s possible to mistake implantation bleeding for a very light period at first, especially if it occurs about when you’d normally expect your period to arrive. Implantation bleeding can also sometimes be accompanied by mild cramping.

However, there are some clues to pay attention to. Although every woman’s period is different, implantation bleeding is usually very light, or even just a little spotting. So, it’s likely that there will be much less blood than you usually see during a regular period – especially if you usually have relatively heavy periods.

Keep in mind, though, that heavier bleeding may also occur in early pregnancy, and this is not always a problem either, so it’s always best to see a doctor if you think you may be pregnant and experience any kind of bleeding.

It’s also worth looking out for other early signs of pregnancy. Some of those signs might include more frequent trips to the loo, fatigue or morning sickness.

Not all mums-to-be experience these symptoms straight away though, especially during the very early weeks, so if you haven’t yet noticed anything other than some very light bleeding or spotting – or even if there are no signs at all – it doesn’t necessarily mean you’re not pregnant.

When Does Implantation Bleeding Happen?

You may notice implantation bleeding anytime between 7 to 14 days after conception. So, if you have a regular cycle, there’s a change it could happen more-or-less when you’d expect to have your next period (if you weren’t pregnant).

This is why some people mistake implantation bleeding for a very light period, especially if they weren’t expecting to get pregnant.

For someone with a regular, 28-day menstrual cycle, the timing of implantation bleeding could look something like this:

  • Ovulation – the release of an egg from at least one of your ovaries – takes place around 14 days after the first day of your last period.

  • If you have sex around the time you ovulate, the egg may be fertilised by sperm within about 24 hours after ovulation – this is how long the egg usually lives after being released.

  • After fertilisation, the egg takes five or six days to travel via the fallopian tube to your uterus, where it starts to embed itself into the lining – this is implantation and it means you’re pregnant!

  • The implantation bleeding could happen sometime after this, as the embryo burrows down into the lining of your uterus.

Keep in mind that it’s difficult to know exactly when you ovulate or conceive, especially if your cycle is irregular. When you last had sex is not a reliable indicator either, because sperm can live for up to seven days inside a woman’s reproductive tract. This means conception might not occur for several days after sex.

How Long Does Implantation Bleeding Last?

Implantation bleeding usually clears up in a few days at most, but even light bleeding or spotting that lasts for longer than this is not always a cause for concern.

This is because there are other causes of light bleeding in early pregnancy – including hormonal changes, a yeast infection or polyps – that are not necessarily harmful to your pregnancy. Some of these may last longer than implantation bleeding.

If you’re unsure whether you’re experiencing implantation bleeding or some other kind, get in touch with your doctor or midwife to arrange an examination. This is really the only way to find out whether the bleeding is harmless or potentially more serious.

Should You Take a Pregnancy Test During Implantation Bleeding?

You can take a home pregnancy test during implantation bleeding. Keep in mind that the pregnancy hormone human chorionic gonadotropin (or hCG) that pregnancy tests detect only starts being produced in your body the moment the fertilised egg is implanted in the uterus.

This is also the trigger for implantation bleeding, so when you notice any spotting it might still be very early in your pregnancy.

The earlier you take the test, the less hCG there is to detect, meaning that the test may not yet be accurate. Some tests are more sensitive than others, and some claim to detect hCG as early as eight days after conception.

If you have the patience to wait, however, you’ll get a more accurate test result if you leave it until at least until after the day your period would normally be due. If you’re not sure when that is, then for more accurate results try at least 21 days after you last had unprotected sex.

If you get a positive test result, get in touch with your GP or a midwife to confirm your pregnancy and start your antenatal care.

While you’re waiting for your first antenatal appointment, you can use our handy due date calculator to get an estimate of when your little one might arrive.

When to See the Doctor

Implantation bleeding is usually nothing to worry about, but it’s best to talk to your doctor or midwife about any bleeding you experience during pregnancy.

Keep in mind that there are other causes of bleeding in early pregnancy, and many of these are not a cause for concern, although they do need to be checked out. For example, pregnancy hormones may cause changes to the cells on the cervix (the opening to your uterus), resulting in bleeding.

Even a heavier ‘gush’ may be harmless, and the colour of the bleeding may be light, pink, dark or red, so try to stay calm and make an appointment with your doctor, who’ll be able to determine whether it’s implantation bleeding or if there’s another cause.

Although light bleeding or spotting in early pregnancy can be totally normal, there are some reasons for bleeding in early pregnancy that need to be addressed immediately. These can include infection, miscarriage, or ectopic pregnancy.

FREQUENTLY ASKED QUESTIONS

  • Every woman’s period is different, but – as a general rule – if it seems much lighter than your usual period it might be implantation bleeding.

    Other early signs of pregnancy – such as feeling sick or tired, food cravings or the frequent urge to pee – can also indicate that it was more likely to be implantation bleeding than a menstrual period.

  • You might see light traces or smears of blood on a sanitary pad or on toilet paper when you wipe.
  • Not all mums-to-be experience implantation bleeding, but for those who do there is usually only light bleeding or spotting.
  • There may not be any noticeable signs at all, but some women experience light bleeding or spotting just after implantation. Other early pregnancy symptoms that you may (or may not) notice soon after implantation include:
    Tiredness
    More frequent urges to pee
    •Feeling/being sick (morning sickness)
    •Aversion to certain smells or tastes
    •Cravings for unusual foods
    •Sore breasts.
  • Implantation bleeding happens after a fertilised egg attaches to the lining of the uterus. This could be about 7 to 14 days after conception. If you have regular periods, it can happen around the time you would expect your period.
  • Implantation bleeding usually lasts for a few days at most. Light bleeding or spotting that lasts for longer than this may be due to other causes. Not all of these are necessarily a cause for worry, but always get tell your doctor or midwife about any bleeding you experience during pregnancy.

Implantation bleeding may sometimes be mistaken for a light period, especially if you have light or irregular periods normally. But these drops of blood could also be a sign that you’re about to embark on a very exciting journey. If you’re at all unsure, check with your doctor. If you are pregnant, congratulations! Read up on how far along you are in this wonderful journey, and find out what’s to come over the coming weeks, months and trimesters.

How we wrote this article The information in this article is based on the expert advice found in trusted medical and government sources, such as the National Health Service (NHS). You can find a full list of sources used for this article below. The content on this page should not replace professional medical advice. Always consult medical professionals for full diagnosis and treatment.