Implantation bleeding: What is it and how to tell if it’s a period


by Lesley Gilchrist |
Updated on

You may think that bleeding or spotting is the last thing you want to see when you're trying to conceive – but in fact this light spotting could be implantation bleeding, which is one of the early signs that you are pregnant. About 25% of women will experience implantation bleeding as an early pregnancy indicator.

Light bleeding or spotting in your wet watery pregnancy discharge doesn't confirm that you are pregnant, but some women do experience it just after they've conceived.

So, just what does this bleeding mean, why does it happen and how long does this implantation bleed last?

What is implantation bleeding?

Bleeding in early pregnancy, known as early pregnancy [implantation bleeding]{href='https://www.nhs.uk/conditions/pregnancy-and-baby/vaginal-bleeding-pregnant/' target='_blank' rel='noopener'} or implantation spotting, can be a sign that you are pregnant.

The 'bleed' happens in some women when the embryo lodges itself into the side of the uterus, 'implanting' and causing some light spotting in some women.

How long does implantation bleeding last?

Implantation bleeding usually lasts around 1-2 days, but can last anything from a few hours to spotting on and off for many days, and be extremely light, and stay light. It tends to occur a few days before your period would be due. A study of 151 pregnant women who experienced implantation bleeding found that most episodes of bleeding occurred at least 5 days after implantation.

As with everything, everyone is different – some women may find that the implantation bleeding lasts as long as their normal period, some won't see any spotting at all.

When does implantation bleeding occur?

If you do get implantation bleeding, it commonly happens around the three weeks pregnant or four weeks pregnant mark.

Implantation spotting can also confuse the dates your midwife may give you for your estimated birth date, based on the first day of your last menstrual period. When you do see your midwife they will ask you when your last menstrual period was and also if it was ‘lighter’ than normal. From this, they can deduce whether or not this was an implantation bleed and ‘date’ your pregnancy as 4 weeks earlier.

This is important when it comes to timing your 12 week or ‘dating’ scan; too late and you may miss the window for some of the screening tests that are offered.

However, it can be difficult to tell the difference between implantation bleeding and your period. Dr Sameer Kumar, MBBS., MS ., FMAS, says that there are many reasons for mid-cycle spotting, but one of the most common is ovulation: "The most common cause of mid-cycle spotting is ovulation bleed which is physiological in most women," he adds.

What is implantation?

Once your egg has been fertilised it then has to travel through your fallopian tube, into your womb and burrow into the lining of your womb, or ‘implant’. This stage, when it attaches to the lining, usually takes around seven days from fertilisation.

The rule of thumb is that ovulation occurs around two weeks after the first day of your last period, and fertilisation around 24-36 hours after ovulation. To confuse things a little more, sperm can survive for up to seven days, so the day that you had intercourse may not be the date you conceived. Sperm can easily wait up to a week in your fallopian tube for the egg, which in contrast will usually only live for 24-36 hours.

Because of this, it can be tricky to calculate a due date for your baby. Tracking your menstrual cycle carefully can make things a lot easier.

What does implantation bleeding look like?

The blood is usually brown or pink and is quite light, usually contained in a panty liner, rather than a sanitary pad.

Implantation bleeding colour is different from the darker red blood associated with menstrual bleeding, however, many women begin their period with this type of blood loss and if they’re not expecting to be pregnant may mistake it for a regular period.

Implantation bleeding colour is different from the darker red blood associated with menstrual bleeding or ovulation spotting, however, many women begin their period with this type of blood loss and if they’re not expecting to be pregnant may mistake it for a regular period.

Most women with implantation bleeding will feel that their period was early, very light and use words such as ‘spotting’.

This ‘spotting’ may continue for 2-4 days in some women, and for those not expecting to be pregnant may simply mistake this for a ‘light’ period and think nothing else of it, until they miss their next period.

Ingefleur, a fertility homeopath and YouTube content creator, has a great video explaining what implantation bleeding can look like. She says implantation bleeding can be "any colour of the rainbow...watery pink, red, brownish, cervical mucus that is blood streaked or little red dots."

Video: Implantation bleeding vs period: 5 ways to know the difference

Is implantation bleeding a sign of miscarriage?

Implantation bleeding is not a sign that there is anything wrong with the pregnancy and there are no links to implantation bleeding and miscarriage.

Implantation bleeding is not a sign that there is anything wrong with the pregnancy and there are no links to implantation bleeding and early symptoms of miscarriage.

If you do think that you may have had a lighter than normal menstrual period it’s probably a good idea to take a pregnancy test one week later.

Not only will this confirm your pregnancy, it also lessens the chances of your midwife incorrectly calculating the date for your first scan and therefore limiting your access to certain screening tests that can be done.

Meet the expert

Lesley Gilchrist, BSc Midwifery Studies, MSc Clinical Research Methods, has been a midwife since 2003, and has extensive experience as a labour ward co-ordinator and as a community midwife.

Just so you know, whilst we may receive a commission or other compensation from the links on this website, we never allow this to influence product selections - read why you should trust us
How we write our articles and reviews
Mother & Baby is dedicated to ensuring our information is always valuable and trustworthy, which is why we only use reputable resources such as the NHS, reviewed medical papers, or the advice of a credible doctor, GP, midwife, psychotherapist, gynaecologist or other medical professionals. Where possible, our articles are medically reviewed or contain expert advice. Our writers are all kept up to date on the latest safety advice for all the products we recommend and follow strict reporting guidelines to ensure our content comes from credible sources. Remember to always consult a medical professional if you have any worries. Our articles are not intended to replace professional advice from your GP or midwife.