Implantation Bleeding or Your Period? Everything You Need to Know

Although you know your body better than anyone else, it’s still possible to mistake implantation bleeding for your period. What exactly is implantation bleeding, and how can you tell if you’re experiencing it?

Implantation bleeding is light spotting that can happen when a fertilized egg embeds itself into your uterus lining, also known as the endometrium. Implantation typically occurs 10–14 days after fertilization—although the timing can vary—and it’s a natural part of early pregnancy. 1

After fertilization, the embryo takes about 30 hours to travel through your fallopian tube before reaching your uterus. 2 By the time it reaches this stage, it has transformed into a blastocyst, a rapidly dividing cluster of cells. 3

Your endometrium will thicken (under the influence of estrogen) to create a nourishing environment, which makes it possible for the embryo to embed itself securely. When the blastocyst burrows into your uterine lining, it may tear open tiny blood vessels, causing a small amount of vaginal bleeding. 4

Not everyone experiences implantation bleeding. It’s estimated to occur in just 15–25% of pregnancies, and many women who do experience it may not even realize what it is, sometimes mistaking it for the start of their period. 5

Implantation bleeding symptoms

Besides light spotting, you may experience other symptoms associated with implantation during early pregnancy: 6

• Mild cramping (usually lighter and shorter in duration than menstrual cramps)
• Nausea
• Breast tenderness
• Headaches
• Mood swings
• Lower back pain

These symptoms aren’t unique to implantation bleeding and could also be ovulation symptoms, the result of menstruation, or something else. The best way to confirm your pregnancy is to take a pregnancy test a few days after missing your period.

Because you’ll usually have implantation bleeding 10–14 days after an egg is fertilized, you may mistake it for an early period. 1 However, there are key differences:

• Color: Menstrual blood is usually bright or dark red, while implantation bleeding is typically pink, brown, or rust-colored.
• Amount: Implantation bleeding is light, unlike a full menstrual flow. This is why it’s often characterized with the word “spotting.”
• Duration: Implantation bleeding typically only lasts a few hours or a few days at most. If it lasts longer, it’s most likely your period. 1
• Clotting: Unlike a period, implantation bleeding doesn’t usually contain clots.

Can you take a pregnancy test if implantation bleeding occurs?

Yes, if you see what you suspect is implantation bleeding, you can take a pregnancy test. However, for the most accurate results, it’s best to wait a few days after the spotting stops, ideally until the day you miss your period.

This allows enough time for hCG (human chorionic gonadotropin), the pregnancy hormone, to build up in your system. 7

If you take the test when you first see blood, it might be too early, which means that if you get a negative result, that doesn’t necessarily mean you aren’t pregnant. You may need to wait a few days and take the test again to be sure.

Other reasons for bleeding in early pregnancy

While implantation bleeding is one possible explanation for early pregnancy spotting, other causes can include: 8

• Cervical irritation: Your cervix is more sensitive during pregnancy, and you might get light spotting after a pelvic exam or sex.
• Vaginal infections: Some infections, particularly sexually transmitted diseases (STIs) like gonorrhea or chlamydia, can cause light spotting. 9
• Early pregnancy complications: Bleeding that is heavy, prolonged, or accompanied by severe pain could indicate an issue like an ectopic pregnancy or miscarriage, which requires medical attention.

If you have any of these issues, your doctor may categorize your pregnancy as a threatened miscarriage. This scary-sounding term doesn’t mean your pregnancy is doomed—it just means your symptoms elevate you into a higher risk category, meaning you may need closer medical supervision.

If you experience severe cramping, dizziness, heavy bleeding, or pain in your shoulders or pelvis, call your doctor immediately.

When to see a doctor

Implantation bleeding is generally harmless, but there are times when you should get a doctor to evaluate early-pregnancy bleeding: 8

• Positive pregnancy test and bleeding: If you have a positive pregnancy test and then experience bleeding, check with your doctor to rule out any concerns.
• Heavy bleeding: Any heavy bleeding, especially if you have clots, should be addressed immediately.
• Severe cramping or pain: Intense pain, particularly one-sided pelvic pain, could indicate an ectopic pregnancy.
• Prolonged bleeding: If bleeding lasts more than a few days or increases over time, call your doctor.

Don’t panic over a little blood—implantation bleeding is a natural part of early pregnancy. Having it doesn’t necessarily mean there’s anything wrong with your pregnancy, nor does its absence. Many healthy pregnancies occur without any implantation bleeding at all.

Just take a home pregnancy test a few days after your missed period for some more definitive answers. If you’re feeling impatient and need to know now, you can also get professionally tested by a doctor to see whether you should start stockpiling diapers.