What other symptoms come with implantation bleeding

Implantation bleeding is light bleeding that may happen about six to 12 days after conception. It may be caused by a fertilized egg implanting in the blood-rich lining of your uterus. Implantation bleeding can be an early sign of pregnancy, but some women mistake it for menstrual blood because it may happen around the time they expect their period.

Implantation bleeding

Implantation bleeding is light bleeding that a small percentage of pregnant women have at about six to 12 days after fertilization. Here's the theory behind why it happens:

After the sperm fertilizes the egg, it starts the three- or four-day trip from the fallopian tube to your uterus. During this time, it divides into hundreds of identical cells. Meanwhile, your ovaries release estrogen that causes the lining of the uterus (the endometrium) to thicken and develop more blood vessels. The uterine lining is preparing to host the quickly growing egg that will soon become an embryo.

Once the egg enters the uterus, it's called a blastocyst, a tiny ball of several hundred cells. A day or two later, it begins burrowing into the blood-rich lining of your uterus, where it continues to grow and divide. As it burrows into the endometrium, the blastocyst may cause little blood vessels to burst, resulting in a small amount of vaginal bleeding.

Implantation bleeding symptoms

In addition to light bleeding, some women also have these other implantation symptoms:

• Light cramping (less than with a normal period)
• Nausea
• Breast tenderness
• Lower back pain
• Mood swings
• Headaches

Note that these symptoms are no guarantee that you're pregnant – they can also be signs of ovulation or PMS. Taking a home pregnancy test is the best way to find out if you're pregnant. (Though you may have to wait a few more days to get an accurate result.)

If you do get your period instead of a positive pregnancy test, and haven't yet scheduled a preconception visit with a midwife or doctor, now is a good time to do so.

When does implantation bleeding occur?

Implantation bleeding tends to occur during the week before you would expect your period, or about six to 12 days after conception. This is around the same time a fertilized egg would be attaching itself to the uterine lining.

How long does implantation bleeding last?

Unlike a regular menstrual period, implantation bleeding usually lasts no more than a day or two. This is the amount of time it takes for the fertilized egg to become implanted into the lining of the uterus.

How common is implantation bleeding?

By some estimates, about 15 to 25 percent of women experience implantation bleeding. Some women may think they’re having a light period when they see the spotting. They may not realize they're pregnant.

How can I tell if it's implantation bleeding or my period?

Here's how to tell whether your bleeding is more likely to be implantation bleeding or your period:

• Amount of blood. Implantation bleeding is a lot lighter than a typical period. It's usually just a little spotting.
• Length of time. Most women bleed for three to seven days during their period. Implantation bleeding often lasts only one to three days.
• Color. Menstrual blood is usually bright red or dark red, but implantation bleeding tends to be a light pink, brown, or rust discharge.
• Clotting. Many women bleed enough during their period that some of the blood clots or becomes like a gel. Implantation bleeding is too light to clot.

When to see a doctor for bleeding in early pregnancy

If you continue spotting even after a positive pregnancy test, or if you develop other symptoms (such as pelvic or abdominal pain, dizziness, or lightheadedness), call your provider immediately.

You may need an exam to make sure you don't have an ectopic pregnancy. This happens when the fertilized egg grows outside the uterus, usually in a fallopian tube. (It's possible to have an ectopic pregnancy even if you don't get a positive result on a pregnancy test.)

Bleeding or cramping in early pregnancy may also be a sign of an impending miscarriage. But many women spot in the first trimester for no apparent reason and go on to have a completely normal pregnancy.

Learn more:

Quiz: Am I pregnant?

Video: What is implantation bleeding?

• Implantation bleeding is a normal, early sign of pregnancy and typically lighter than your period.
• Implantation bleeding will usually be pink or light brown and have a thin, watery consistency.
• It's possible to experience implantation bleeding around the same time as you would your period.

After conception, when the sperm cell joins with the egg, the fertilized egg moves down the fallopian tube to the uterus and attaches to the uterine lining. This is called implantation, and it can cause light bleeding or spotting, but not every woman will experience it during pregnancy.

Implantation bleeding is normal and usually doesn't indicate a problem, according to the American College of Obstetricians and Gynecologists. But you might not know whether it is your period or implantation bleeding. Here's how to tell the difference.

When does implantation bleeding occur?

Implantation bleeding occurs about 10 to 14 days after conception. Because that's usually around the same time you would normally have a period, you might confuse implantation bleeding with a light period. 

For women who are trying to get pregnant, they might think, "This isn't my normal period. I should take a pregnancy test," says Melody Baldwin, an OB-GYN at Duke Health. But for women who don't have pregnancy on their radar, they might just think their period was lighter than usual, she says.

How long does implantation bleeding last?

Implantation bleeding typically lasts a couple of days, and "it's generally less heavy, shorter, and less painful than a typical period would be," Baldwin says. 

When the fertilized egg implants in the uterus, it disrupts part of the uterine lining, and that causes the bleeding, Baldwin says. 

The resulting bleeding is small because the embryo is small at that point, and it disrupts only one area of the uterine lining, she says. 

By comparison, during your period, the blood comes from the uterus shedding its lining. That creates a heavier flow than the disruption to the uterine lining during implantation.

There does not seem to be a difference in implantation bleeding based on whether the woman has been pregnant before, says Leena Nathan, an OB-GYN at UCLA Health Westlake Village. 

Is it implantation bleeding or my period? 

The key difference between implantation bleeding and your period is that implantation bleeding flow is typically lighter and lasts only a couple of days. 

However, if you usually have a light period to begin with, it may be difficult to distinguish between the two.

Some other signs to look for are early pregnancy symptoms, Nathan says. These may include:

• Breast tenderness
• Bloating
• Fatigue
• Nausea
• Mild cramping

If you have cramping with implantation bleeding, it would be less intense than typical period cramping, Baldwin says.  

Also, for some women, implantation bleeding may be a different color, like brown or pink, rather than the typical red you'll see from your period. It also usually doesn't involve clotting, Nathan says.

The best way to know if it's implantation bleeding is to take a pregnancy test. 

"Most of the pregnancy tests that are commercially available now would detect a pregnancy around the time of a missed period, which is about the time that implantation bleeding occurs," Baldwin says.

If you have bleeding and take a test that is negative, Nathan recommends repeating the test in a few days.  

Implantation bleeding is fairly common. "It's something that we see relatively often. We field a lot of phone calls about it," Baldwin says. 

Insider's takeaway 

Although implantation bleeding doesn't usually require medical attention, there are some exceptions. 

For patients who don't have any pregnancy complications, implantation bleeding is usually nothing to worry about, Baldwin says. But If you are unsure about what's going on, it's probably a good idea to call your OB-GYN. 

"What I always feel bad about is when I have a patient that says 'I didn't know if I was worrying too much, and I didn't want to call and bother you,'" Baldwin says. "Patients can always call and clarify this with us, because that would give us the opportunity to take care of something that might not be typical or normal. And then it also gives us the opportunity to reassure them," so they don't keep worrying until their next appointment, she says.

Allison Torres Burtka is a freelance writer and editor in metro Detroit. Her writing has been published in the Guardian, espnW, Women's Running, the Sierra Club's Sierra magazine, Crain's Detroit Business, and other outlets. She writes on topics like health and wellness, sports, environment, sustainability, and business leadership. To see more of her work, visit atburtka.journoportfolio.com.

Read more Read less

Does implantation bleeding have other symptoms?

What accompanies implantation bleeding?

What comes first implantation bleeding or pregnancy symptoms?