Bleeding during pregnancy: when it's a warning sign and what to do

Translated from the original Brazilian Portuguese article with the help of artificial intelligence. Clinical review, when applicable, was done on the Portuguese version. Read the original in Portuguese

Seeing blood during pregnancy is frightening.

Even if it's just a few drops on the toilet paper, it's hard not to immediately think:

“Could something have happened to the baby?”

The first important thing to know is this: bleeding during pregnancy does not automatically mean the pregnancy is being lost.

Light bleeding is relatively common, especially in the first trimester. The American College of Obstetricians and Gynecologists (ACOG) estimates that it occurs in about 15% to 25% of pregnancies in the first three months.

At the same time, there are situations in which bleeding may indicate a complication that needs prompt care.

That's why it isn't a good idea to try to work out the cause based only on the amount or color of the blood.

In Brazil, the Ministry of Health considers vaginal bleeding during pregnancy a sign that should lead you to seek evaluation at a health service.

Is bleeding in early pregnancy common?

It can happen.

In the first weeks, some people have only small pink, reddish or brown spots.

Possible causes include changes in the blood vessels of the cervix, light bleeding after sex or gynecological exams, and very early bleeding associated with implantation.

However, there are other causes that need to be investigated, such as:

infections;
pregnancy loss;
ectopic pregnancy;
other pregnancy complications.

In other words:

bleeding does not necessarily mean you are losing the pregnancy.

But it's also not possible to say everything is fine just by looking at the bleeding at home.

Is brown bleeding less worrying?

Not always.

The color can help the health professional understand what is happening, but it does not on its own determine how serious the situation is.

Bleeding may appear as:

small pink spots;
red blood;
brownish discharge;
a flow similar to a period;
bleeding with clots.

Brown blood usually means blood that took longer to leave the body, but that doesn't identify its cause.

Likewise, bright red blood alone doesn't allow you to conclude that there is a complication.

What matters is the full picture:

amount + duration + pregnancy week + presence of pain + other symptoms.

What about that light bleeding after sex?

During pregnancy, the cervix has a richer blood supply.

This means it can bleed more easily, including after sex or a vaginal exam. ACOG describes light bleeding in these situations as something that can happen during pregnancy.

Even so, tell the professional or service that is following your pregnancy about the episode.

Especially if the bleeding:

continues;
increases;
keeps coming back;
comes with pain;
happens later in pregnancy.

Does bleeding mean a miscarriage?

Not necessarily.

Vaginal bleeding can happen with a pregnancy loss, usually with or without cramps.

But light bleeding in early pregnancy can also happen in pregnancies that continue normally. ACOG itself points out that early bleeding does not necessarily mean a miscarriage.

Depending on the pregnancy week and the symptoms, the evaluation may involve tests such as:

ultrasound;
physical exam;
beta-hCG hormone level in certain situations;
other tests decided by the health team.

Sometimes, especially when the pregnancy is still very early, a single test can't answer everything right away.

It may be necessary to follow how things evolve before reaching a conclusion.

Pain on one side plus bleeding deserves special attention

In early pregnancy, one of the conditions health professionals need to consider when bleeding comes with pain is ectopic pregnancy.

It happens when the pregnancy develops outside the uterine cavity, most often in one of the fallopian tubes.

Besides bleeding, there may be:

abdominal or pelvic pain;
pain mainly on one side;
shoulder pain;
dizziness;
weakness;
fainting.

An ectopic pregnancy can cause internal bleeding and requires medical treatment.

If bleeding comes with severe pain, marked weakness, dizziness or fainting, seek emergency care immediately.

What about bleeding after the middle of pregnancy?

This is when extra care is needed.

Bleeding later in pregnancy may be related to changes in the cervix, the start of labor or problems involving the placenta, among other causes.

ACOG advises that any bleeding later in pregnancy be reported immediately to the obstetric team or evaluated at the hospital.

Placenta previa

The placenta is attached very close to, or partially or completely covering, the opening of the cervix.

One possible sign is vaginal bleeding, often painless.

Placental abruption

The placenta starts to separate from the wall of the uterus before the baby is born.

It can cause:

bleeding;
abdominal pain;
back pain;
contractions or hardening of the uterus.

It's a situation that requires urgent evaluation.

Labor

Closer to the birth, a small amount of blood mixed with mucus can be part of losing the mucus plug and the beginning of changes in the cervix.

Even so, especially before 37 weeks, bleeding associated with contractions, pelvic pressure or a change in vaginal discharge needs to be evaluated by the obstetric team.

I'm bleeding. What do I do now?

Don't try to figure out on your own whether the bleeding is “normal”.

Contact your designated maternity hospital, your obstetrician or a health service and tell them you are pregnant and have had bleeding.

When did it start?

Was it just spotting or an amount similar to a period?

Have you had sex or any exam recently?

These details can help the team decide how urgent it is and which tests are needed.

In Brazil, the Ministry of Health advises seeking care when there is vaginal bleeding during pregnancy.

When do you need to go to the emergency room immediately?

Don't wait for a scheduled appointment if the bleeding comes with signs such as:

heavy bleeding;
severe abdominal or pelvic pain;
intense pain mainly on one side;
significant dizziness;
weakness;
feeling faint or fainting;
marked paleness;
shoulder pain together with abdominal pain or bleeding;
painful contractions before 37 weeks;
leaking fluid;
a significant decrease in the baby's movements when you usually already feel them.

Signs of shock, such as a drop in blood pressure, altered consciousness and heavy bleeding, are emergencies.

If the person is fainting, very weak or there is another serious situation that prevents safe travel, SAMU (Brazil's mobile emergency medical service) can be called on 192.

I'm Rh negative. Does that make any difference?

It can.

When a pregnant woman who is Rh negative comes into contact with the baby's Rh positive blood, she may develop antibodies against those blood cells.

Bleeding during pregnancy is one of the situations that can lead to this contact.

So, if you know your blood is Rh negative, tell the team when you seek care for bleeding.

Depending on the pregnancy week, the amount of bleeding and your history, the professional will assess whether anti-D immunoglobulin is indicated. Brazil's Ministry of Health lists vaginal bleeding among the situations with a risk of Rh sensitization.

This is not something to decide on or give yourself.

It's simply important information to share with the team.

Is the amount of blood what determines whether there is danger?

Not on its own.

Heavy bleeding naturally draws more attention and raises concern about significant blood loss.

But light bleeding may also need to be investigated, depending on the stage of pregnancy and the accompanying symptoms.

Likewise, a small spot may turn out to have a harmless cause.

“It was red, so I'm definitely losing the baby.”

None of these conclusions can be drawn just by looking at the blood.

What if the bleeding stops on its own?

Even if it has stopped, let the professional or service following your pregnancy know.

When and how the bleeding happened is still relevant information for your prenatal care.

Whether an exam is needed will depend on the stage of pregnancy, the amount, the accompanying symptoms and each person's history.

Bleeding after birth is a different situation

After the baby is born, there is normally a bloody discharge called lochia.

It starts out redder and tends to decrease and change in appearance as the uterus recovers.

This is different from vaginal bleeding during pregnancy and has its own guidance.

Very heavy postpartum bleeding, a sudden increase in flow, very large clots, a foul smell, fever, weakness or dizziness may indicate complications and need to be evaluated. ACOG considers it a warning sign after birth when bleeding soaks through one or more pads in an hour or when very large clots are passed.

At Nilu, we cover this topic separately because care after the birth is different from care during pregnancy.

Most important: don't try to interpret everything on your own

Seeing blood during pregnancy really messes with your head.

It's very easy to look at the amount, search for photos online and spend hours trying to figure out whether it looks “normal”.

But photos can't tell you:

where the placenta is;
whether the cervix has changed;
where the pregnancy is implanted;
how the baby is doing;
where the bleeding came from.

That requires an evaluation.

If you're going through this right now, contact the maternity hospital, your obstetrician or a health service and explain exactly what happened.

In Nilu, you can also log your symptoms and chat with Luna to organize important information before talking to the health team — for example, your pregnancy week, when the bleeding started, how much there was and any accompanying symptoms.

But when there is bleeding during pregnancy, especially with severe pain, dizziness, fainting or a large amount of blood, Luna does not replace medical care.

Sources consulted

Brazil's Ministry of Health — Low-Risk Prenatal Care Pathways (“Linhas de Cuidado do Pré-natal de Baixo Risco”): Brazilian guidance on evaluation and referral when there is vaginal bleeding during pregnancy.

Brazil's Ministry of Women / Ministry of Health: recommendations updated in 2026 on warning signs during pregnancy and when to seek care.

American College of Obstetricians and Gynecologists (ACOG): causes of bleeding in early and late pregnancy, pregnancy loss, ectopic pregnancy and placental problems.

NHS — National Health Service: information on the types, possible causes and evaluation of vaginal bleeding during pregnancy.

*This content is informational and does not replace medical evaluation. Vaginal bleeding during pregnancy should be reported to and evaluated by a health service, following the guidance of the team responsible for your prenatal care.*