Black Period Blood During Pregnancy: Causes and Concerns

We learn to associate menstrual blood with the color red, but plenty of women have seen shades across the color spectrum—black included. When you’re pregnant, however, black discharge or blood is a signal to visit your OBGYN to ensure both your and your baby’s health is intact. Understanding the nuances of period blood color meaning can provide insight into what your body is going through.

Generally speaking, vaginal bleeding at any point during a pregnancy deserves care and consideration. Knowing the difference between regular discharge vs pregnancy discharge can give you an idea of when something could be concerning. While some light bleeding can occur in healthy pregnancies—like implantation bleeding in the early stages of pregnancy—other causes can indicate a medical condition or a disruption in a pregnancy’s progress.

Whether you’re currently pregnant or planning on growing your family, knowing why you might observe black discharge or dark vaginal discharge can help urgent health decisions with confidence and clarity. Below, find out why this symptom can occur as well as what to do if a black vaginal discharge or dark discharge happens to you.

6 Possible Causes of Black Blood or Discharge

When your period blood is black, it can be a normal part of a healthy menstrual cycle. Dark or black blood usually indicates a heavy blood flow, or that the uterine lining tissues are older: Because they’ve taken longer to shed and exit the uterus, the iron content of your old blood has had more time to oxidize.

For the same reason, blood can also appear black during pregnancy—but healthy pregnancies should rarely arrive with blood to begin with. Bleeding during pregnancy could indicate one of several underlying health conditions, as well as problems with fetal development.

#1 Implantation Bleeding

Sometimes, black period blood pregnant people experience could indicate what’s known as implantation bleeding.

Implantation bleeding doesn’t happen to everyone, but it can occur when a fertilized egg embeds itself in the lining of your uterus. This type of blood is usually very light spotting, typically appearing in colors like:

• Pink
• Brown
• Red
• Black

If you think you’re experiencing implantation bleeding, it’s still important to monitor your symptoms. Normal implantation bleeding lasts between 1 and 2 days, with a very light flow, and with no pain or cramping of the abdomen. The difference between period cramps vs. early pregnancy cramps is also crucial to understand in this context, offering additional clues about your body’s signals.

#2 Infection

Uterine and vaginal infections aren’t pleasant, but they do happen. The female reproductive system has its own micro-ecology (vaginal flora) that can be as subject to imbalance as other areas of the body, like your digestive system or your skin.

Sometimes, vaginal infections can cause darker menstrual discharge or blood. A dark brown discharge or black vaginal discharge can be triggered by a disruption or overgrowth of certain kinds of bacteria or by a foreign object being stuck in your vagina, like a tampon. Similarly, conditions like watery period blood could signal changes in your menstrual cycle or early pregnancy signs, necessitating a deeper understanding of your body’s messages.

Other symptoms of infection to look out for include:

• A foul odor
• Pain in the pelvic area
• Painful urination (dysuria)
• Fever
• Vaginal itching, swelling, or discomfort

It’s best to regard any of these symptoms as a prompt to reach out to a healthcare provider as soon as possible. Infections can often be treated with antibiotics, but expecting moms may need more monitoring and care to ensure their baby’s health is protected.

#3 Pelvic Inflammatory Disease

Pelvic inflammatory disease (PID) occurs when a bacterial infection causes the female reproductive organs to become inflamed. Having a preexisting STI, not using condoms during sex, or frequently douching can make you more likely to develop it.

People with PID often experience lower abdominal or pelvic pain, as well as the following symptoms:

• Heavy discharge
• Foul-smelling discharge
• Pain during sex
• Pain during urination, difficulty urinating, or frequent urination
• Vaginal bleeding, especially between periods
• Fever
• Chills

PID and its symptoms often throw normal menstrual cycles out of whack, and can often change the appearance, texture, and bleeding patterns of menstrual blood.

If you think you may have PID, it’s important to seek a diagnosis promptly, as untreated PID can cause chronic pelvic pain and have long-lasting effects on female fertility. People with PID are at higher risk of:

• Ectopic pregnancy
• Developing reproductive abscesses
• Infertility

In non-pregnant individuals, PID is typically treated with antibiotics. However, if you’re pregnant and have a PID flare-up, you may need hospital care and more attentive treatment.

#4 Endometriosis

Endometriosis is another reproductive health condition that causes uterine tissue to grow outside of the uterus. During menstruation, these extrauterine tissues are shed and may appear as dark brown discharge or black menstrual discharge.

Endometriosis can be immensely painful—especially during menstruation—in part due to the scar tissue formed from abnormal bleeding. Endometriosis can also cause:

• Abnormally heavy periods
• Pain during sex
• Trouble getting pregnant

People with endometriosis frequently experience difficulty getting pregnant. They’re also considered a high-risk group for certain pregnancy complications, including:

• Placental abruption, when the placenta detaches from the uterine wall
• Preeclampsia
• Gestational diabetes
• Hypertension
• Preterm birth or stillbirth

If you’re pregnant and think you may have endometriosis, reach out to a healthcare provider as soon as you can. They can help you devise treatment plans for during and after your pregnancy.

#5 Uterine Fibroids

Uterine fibroids are growths that contort the structure of the uterus and, in some cases, disrupt blood flow during menstruation. This can result in blood retention, which can ultimately show up as black (oxidized) blood and discharge.

Though benign, uterine fibroids can impact menstrual patterns and symptoms significantly. In addition to altered period blood color, people who have them may notice:

• Pelvic pain
• Longer menstrual cycles
• Heavy menstrual bleeding

Not everyone with uterine fibroids experiences symptoms, and fortunately they seldom complicate pregnancies. While expecting moms can’t remove fibroids during pregnancy, many treatment options are available—including both medication and surgery—to effectively treat them after your baby is born.

#6 Miscarriage

If you’re already several weeks into a pregnancy, any persistent bleeding—whether red, brown, or black blood—may indicate a miscarriage.

Missed miscarriages (also called silent miscarriages) are a type of pregnancy loss that are most commonly associated with black blood or discharge. These miscarriages can occur any time before 20 weeks of pregnancy. If you have one, you may also notice:

• Pain in your abdomen and lower back
• Cramping
• Diminished pregnancy symptoms (like headaches, frequent urination, or morning sickness)

Often, silent miscarriages resemble a period, arriving with cramping, breast tenderness, and fatigue. Some pregnant people don’t notice symptoms while they’re having one; many aren’t aware they are pregnant when they occur.

Care For and Recovering From a Missed Miscarriage

Whether you’ve been trying for a baby or are several weeks or months along, miscarriage is undeniably one of the most difficult experiences a mother can go through. It’s not easy to remain emotionally steady if you have one, but it’s important to reach out to a provider as soon as possible to rule out other causes and confirm you’ve had one.

If your healthcare provider confirms a miscarriage, they’ll likely recommend several steps to ensure you make a successful physical, emotional, and psychological recovery.

Guiding the Miscarriage

Some miscarriages resolve on their own within 7 and 14 days of onset. If the miscarriage isn’t associated with an infection, complication, or a preexisting health condition, you have the option of letting the miscarriage take its course on its own.

That said, many parents choose to help along the process by taking medication or undergoing surgery to dispel tissues from the uterus. Speeding up the process may help some parents digest their experience, clearing emotional space to try again for a baby later on.

Fertility Consultations

If your miscarriage was caused by an undiagnosed health condition, your provider might encourage you to meet with a fertility counselor to discuss your options for getting pregnant safely. Even if you’re in good health, meeting with a specialist may also help some parents feel more supported once they start the process again.

Many clinicians advise waiting 6 or so months before trying again for a baby after experiencing a miscarriage. However, many parents can get pregnant again within 3 months of a pregnancy loss.

Monitoring Your Well-Being

Experiences with miscarriage are highly individual: some people may be relatively unaffected by them, while others may have profound feelings of grief or loss to work through.

No matter what kind of attachment you had to your pregnancy, it’s helpful to give yourself space and time to process the experience, welcoming any emotion that arises. Common feelings and experiences to move through after miscarriage include:

• Fear and shock
• Anger and resentment
• Depression, hopelessness, emptiness
• Changes in eating, sleeping, or movement patterns
• Isolation and withdrawal
• Difficulty concentrating
• Fatigue or lack of motivation
• Memory problems
• Anxious thought patterns
• Physical aches and pain

These are just some of the countless ways to process a pregnancy loss. Discussing your feelings with a partner, trusted friend, or therapist may provide an outlet to vocalize feelings and give them room to evolve. With patience and time, you can get back on the path to parenthood—no matter what the journey looks like for you.

Lastly, the complexities surrounding fertility and menstrual health raise questions like, can you get pregnant on your period, emphasizing the importance of accurate information and guidance during these critical times.

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At SneakPeek, our commitment is to provide accurate, up-to-date, and reliable information to empower our readers. Our content is thoroughly researched, reviewed by medical experts, and fact-checked to ensure its credibility. We prioritize the well-being and education of our readers, and our editorial policy adheres to the highest standards of integrity and accuracy in all our articles.

This post has been reviewed for accuracy by the following medical professional:

Katie Smith, MSN, APRN, CNM

Katie Smith is a seasoned Certified Nurse Midwife and a nurturing mother to six children, offering a unique blend of professional expertise and personal experience. She is the founder of Birth Your Way Midwifery and Women’s Wellness Center in Bay County, Florida. Katie's comprehensive approach to care is informed by her hands-on experience in motherhood and her passion for empowering women through their birthing journey. Her dedication extends beyond her center as she actively engages in community wellness and family health education.

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9. PsychCentral. Miscarriage Grief: How to Cope with the Emotional Pain. https://psychcentral.com/health/miscarriage-grief#emotional-cognitive-and-physical-reactions