Spotting during pregnancy is common, especially in the first trimester. Between 15% and 25% of all pregnant people experience some bleeding or spotting in the first 12 weeks, and many go on to have perfectly healthy pregnancies. That said, spotting can occasionally signal a problem, so understanding what’s behind it and what to watch for matters.
What Spotting Looks Like
Spotting means noticing a few drops of blood, usually pink, red, or dark brown, on your underwear or when you wipe. It’s light enough that a panty liner would catch it without filling up. This is different from bleeding, which produces a heavier flow closer to what you’d see during a period. That distinction is important because heavier bleeding, particularly the kind that soaks a pad every few hours, is more likely to point toward a complication.
Common Causes in the First Trimester
The most well-known cause of early spotting is implantation bleeding. When a fertilized egg attaches to the uterine lining, it can cause light pink or brown spotting that lasts anywhere from a few hours to about two days. This typically happens 10 to 14 days after ovulation, which means it often shows up right around the time you’d expect your period. Many people mistake it for a light period before realizing they’re pregnant.
Hormonal changes during pregnancy also make the cervix more sensitive. Rising estrogen causes a condition called cervical ectropion, where softer cells from the inner cervix become exposed on the outer surface. These cells are more fragile and bleed easily, which is why spotting after sex or after a pelvic exam is so common during pregnancy. This type of spotting is harmless and usually stops on its own within a day.
Subchorionic Hematoma
Sometimes a small pocket of blood collects between the uterine wall and the membrane surrounding the embryo. This is called a subchorionic hematoma, and it’s one of the more common findings when spotting is investigated with an ultrasound in the first trimester. It’s particularly common in pregnancies conceived through fertility treatments like embryo transfer, but it also occurs in pregnancies conceived naturally. Many subchorionic hematomas resolve on their own without affecting the pregnancy.
Spotting in Late Pregnancy
Spotting after 20 weeks deserves closer attention. One possible cause is placenta previa, a condition where the placenta sits low in the uterus and partially or fully covers the cervix. The hallmark sign is bright red vaginal bleeding, usually painless, that appears after 20 weeks. Sometimes it starts as light spotting before a larger episode of bleeding. It can also be triggered by sex or contractions. Placenta previa is typically identified on a routine ultrasound, and your care team will monitor and manage it throughout the rest of pregnancy.
Light spotting can also happen in the final weeks as the cervix begins to soften and thin in preparation for labor. Losing the mucus plug or having a “bloody show” is normal near your due date. But any unexpected bleeding in the second or third trimester should be evaluated, because it can also indicate placental abruption, where the placenta separates from the uterine wall before delivery.
When Spotting May Signal a Problem
Two serious conditions can cause spotting early in pregnancy: miscarriage and ectopic pregnancy.
Miscarriage, defined as a pregnancy loss before 20 weeks, often starts as light bleeding that gradually becomes heavier and is accompanied by strong cramping. Not all spotting leads to miscarriage, but bleeding that intensifies over time or starts to resemble a period flow warrants prompt evaluation.
An ectopic pregnancy occurs when a fertilized egg implants outside the uterus, most often in a fallopian tube. Light vaginal bleeding paired with pelvic pain is frequently the first warning sign. If the tube begins to rupture, symptoms escalate quickly: you may feel sharp abdominal pain, shoulder pain, extreme dizziness, or feel like you might faint. This is a medical emergency.
How Spotting Is Evaluated
If you report spotting to your provider, the evaluation usually combines two tools: a blood test measuring pregnancy hormone levels (hCG) and a transvaginal ultrasound. These work together to confirm where the pregnancy is located and whether it’s developing normally.
Pregnancy hormone levels rise rapidly in early pregnancy, increasing by at least 66% every 48 hours through roughly the sixth or seventh week. Your provider may check your levels twice, spaced 48 to 72 hours apart, to see if they’re rising appropriately. Levels that plateau or rise very slowly can suggest an ectopic pregnancy or a pregnancy that isn’t viable.
On ultrasound, a gestational sac is usually visible by about four weeks and three days after the last menstrual period. The ultrasound can identify the location of the pregnancy, check for a heartbeat, and look for findings like a subchorionic hematoma that might explain the bleeding. In some cases, one ultrasound isn’t enough. If the pregnancy is very early and the sac is too small to evaluate conclusively, a follow-up scan about a week later may be needed before any diagnosis is made.
Symptoms That Need Immediate Attention
Most spotting in pregnancy turns out to be harmless, but certain symptoms alongside bleeding indicate you should seek care right away:
- Heavy bleeding that soaks a pad within an hour or includes clots larger than an egg
- Severe abdominal or pelvic pain that starts suddenly, feels sharp, or worsens over time
- Dizziness, lightheadedness, or fainting
- Shoulder pain, which can be a sign of internal bleeding from an ectopic pregnancy
- Fever of 100.4°F (38°C) or higher
- Passage of tissue from the vagina
Outside of these red flags, isolated spotting that is light, brief, and painless is the most common pattern, and it resolves on its own in the vast majority of cases. Keeping track of the color, amount, and timing of any spotting gives your provider useful information if you do need to be evaluated.