Can implantation bleeding be heavy?

You’ve noticed blood in your underwear, but it’s much lighter than your period. So what is it? While bleeding between your periods, known as spotting, isn’t uncommon, what you might be experiencing is what doctors call implantation bleeding. 

You may not have heard of implantation bleeding before, but it’s pretty common. In fact, a quarter of women experience it in the earliest stage of pregnancy. The confusing thing is that it often comes around the time when you might expect your period to start. So it can be tricky to figure out whether your period has arrived early or if it’s a sign of something else, like implantation.

So, here’s the lowdown on implantation bleeding — from what causes it to how to figure out what’s going on for you.

Key takeaways

• Implantation is the term used to describe when your fertilized egg attaches to your uterine lining. This is the point in your conception journey when you’re officially classed as being pregnant, and it can happen around six to ten days after a sperm fertilizes your egg. 
• You might be curious why this would make you bleed since your fertilized egg is only microscopic at this point. Bleeding can happen because, at the point of implantation, your uterine lining is thick and full of blood vessels. As your fertilized egg embeds into it, it can burst these vessels and cause them to bleed. 
• It’s worth noting that implantation bleeding is generally light and might appear as pinkish-red or brown discharge rather than blood. If the bleeding is heavier than this, then it’s more likely to be your period. 
• You should always reach out to your health care provider if you’re concerned or have questions about bleeding between your periods. 

What does implantation bleeding look like? 

Since implantation bleeding can typically show up around six to ten days after you’ve conceived, it may show up when your period is due. Confusing, right? This is why it can be helpful to know the differences between how they might look. 

“Implantation bleeding is usually lighter than a period. It’s often only spotting and could be as subtle as just pink or brown discharge,” explains Dr. Jennifer Boyle, obstetrician and gynecologist at Massachusetts General Hospital. “You might notice it once or only a few times in a single day, and it certainly shouldn’t last more than two to three days at the very most.”

And, while a tampon, period cup, or pad is pretty essential during your period, you may only notice implantation bleeding as a spot in your underwear or on toilet paper when you wipe. It’ll likely resemble discharge rather than your period. A thin panty liner is usually enough to protect your underwear from stains because implantation bleeding typically isn’t heavy. 

If you’re unsure if the bleeding you’re experiencing is your period, implantation bleeding, or something else entirely, then it’s a good idea to speak to your doctor. 

Can implantation bleeding be heavy?

It can be hard to say if implantation can be heavy as no two cycles are the same, so what you experience may be completely different from other people. 

Generally speaking, though, implantation bleeding is much lighter than a typical period and isn’t heavy or long-lasting. While your period may last around seven days and start light and get heavier, implantation bleeding should last no longer than a couple of days and may appear more like one-off light spotting. 

Dr. Boyle explains that you’ll most likely know what a typical period looks like for you, so trust your gut. If bleeding appears lighter or more sporadic, then it may be implantation bleeding. And if you’re at all worried by it, then reach out to your doctor. 

When does implantation bleeding happen? 

Implantation bleeding has been described as common — around 25% of people experience light implantation bleeding. However, it can be hard to pinpoint exactly when you might experience it because not everyone will. This doesn’t mean implantation hasn’t happened, but you might just not have noticed any spotting in relation to it. Your cycle is totally unique to you, after all. 

If you’re trying to get pregnant, then you might be keeping an eye out for the earliest signs of pregnancy — implantation bleeding can be one of them. Knowing when implantation might have happened for you can also help you understand when you can take a pregnancy test. 

Let’s rewind a little to get a better understanding of what might be going on in your body. Every cycle, one of your ovaries releases an egg. You can use an app like Flo to get a better understanding of when this might happen. If it’s met by a sperm and fertilized, then it may start the journey down one of your fallopian tubes and attach to the lining of your uterus. This is implantation, and it can take six to ten days.

Your uterine lining will be thick at this point and full of blood vessels. When your fertilized egg attaches, it can disrupt these vessels and cause them to bleed, otherwise known as implantation bleeding. Some people also report cramping around this time too. 

This means you may notice implantation bleeding around 10 days after you’ve ovulated. This is sometimes referred to as 10 days past ovulation, or DPO for short. You can get a better understanding of when you might be ovulating, along with some of the signs to look out for, using an app like Flo. 

Can you take a pregnancy test during implantation bleeding? 

If you’re trying to get pregnant, then this is a big question. It can be really difficult not to look for every possible sign and symptom that you could be expecting. This is totally normal. However, since implantation bleeding can show up around the time that you might expect your period, it’s easy to confuse the two. 

“If you have light bleeding around the time you expect your period and are wondering if it’s implantation bleeding, then check with a pregnancy test,” advises Dr. Boyle. 

After your fertilized egg has implanted into the lining of your uterus, your body starts to release a hormone called human chorionic gonadotropin (hCG). This is what at-home pregnancy tests look for in your pee. Your hCG levels start very low in the first few days of pregnancy and rise dramatically in your 1st trimester. This means that if you take a pregnancy test too early in your pregnancy, you risk getting a false negative. 

Ten DPO is still very early to be able to tell if you’re pregnant. Doctors recommend that you hold off until the first day of a missed period before taking a test. However, the waiting can be a real test. It’s important to wait as this window when your period hasn’t arrived is when your hCG levels start rising high enough to be detected by a test once you’ve missed your period. This gives you a better chance of an accurate pregnancy test result.

What else could cause bleeding during early pregnancy?

The sight of spotting during early pregnancy can be really worrying. It’s totally understandable to have questions or be concerned about bleeding in the first few weeks of pregnancy. However, very light bleeding while pregnant is actually very common and occurs in around 15% to 25% of pregnancies. So you can take comfort in knowing that if you experience it, you’re certainly not alone. 

There are a few different things that can cause bleeding in early pregnancy, including: 

• Cervical changes: Your cervix is the muscular tunnel-like organ that connects your uterus to your vagina. It can bleed more easily in early pregnancy if it’s irritated because blood vessels are forming at this time. You might notice bleeding during sex because of this. 
• Cervical polyps: Polyps are small noncancerous growths that develop on your cervix. As your estrogen levels rise during pregnancy, it can cause them to bleed. This might sound really scary, but rest assured that polyps are quite common and usually aren’t something to be worried about.
• Vaginal infections including sexually transmitted infections (STIs): “Some STIs like gonorrhea, chlamydia, and trichomonas can cause spotting and abnormal bleeding. If someone has bleeding that is not a period and they also have abdominal pain, they should see a health care provider. STIs can cause abnormal bleeding during pregnancy and just on their own,” says. Dr. Boyle.

It can be really hard not to jump to conclusions if you notice bleeding during early pregnancy, as spotting can be a sign of baby loss or pregnancy complications such as ectopic pregnancy. This is when your fertilized egg implants outside of your uterus, for example, in your fallopian tube. The egg can’t grow safely here, and it can cause internal bleeding without medical assistance.

If you’re at all worried about bleeding or spotting in early pregnancy, then the best thing to do is speak to your doctor as soon as you can. They may ask you questions about any other symptoms you have. They’ll then be able to provide support and advice.

When to call a doctor

Very light bleeding during early pregnancy isn’t usually something to worry about. However, it can still be really anxiety-inducing, so don’t hold back on letting your health care provider know. They will be able to talk through any symptoms you’ve had, run any relevant tests, and support you.

Dr. Boyle explains that if you have heavy bleeding or any pain in your tummy or back that lasts for more than two days, then you should speak to your doctor immediately.