Implantation Symptoms and the First Signs of Pregnancy

Medically Reviewed By Sanaz Ghazal, MD, FACOG
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Implantation occurs when a fertilized egg attaches to the uterus. The most common symptoms are light bleeding and cramping. The time of implantation can vary, though it generally occurs 6–10 days after a sperm fertilizes an egg. Because implantation symptoms are similar to those of a menstrual period, only a positive pregnancy test can confirm a pregnancy.

However, if you test too early, the result may be negative. This is because it can take several days for your body to produce enough of the pregnancy hormone, human chorionic gonadotropin (hCG), to provide a positive test result.

This article will explain all the possible signs and symptoms of implantation, when to take a pregnancy test, when to contact your doctor, and other frequently asked questions about the implantation process. 

Light bleeding

Cropped image of hands holding a positive pregnancy test
Sergio Marcos/Stocksy United

Light bleeding or spotting may happen in the first 12 weeks after fertilization.

Bleeding and spotting symptoms may occur due to a fertilized egg burrowing itself into the uterine lining. In most cases, this type of bleeding is normal and does not signal a problem with the pregnancy. 

Implantation bleeding is usually pinkish and lighter than you would typically see during a regular period, according to the National Institute of Child Health and Human Development.

Because implantation bleeding usually occurs around the same time as a regular period, some people may mistake this bleeding for a light period. It is possible not to realize you are pregnant until you experience other pregnancy symptoms or take a pregnancy test.

Cramps

Mild cramping in the uterus can be another symptom of implantation. Cramping symptoms may result from a hormonal shift during early pregnancy or the fertilized egg implanting. 

Implantation cramps vary from person to person. You may not experience any cramping. If you have implantation pain, it may feel like a twinge, a dull ache, or mild menstrual cramps.

Other early pregnancy symptoms

A missed period is the most reliable sign of pregnancy. This may occur 1–2 weeks from conception.

In the early weeks of your pregnancy, you may also experience symptoms that include the following:

Early pregnancy symptomWhen it can start
fatigue1 week from conception
sore or tender breasts1–2 weeks from conception
nausea or vomiting2–8 weeks from conception
increased urinationfirst few weeks
mood swingsfirst few weeks
headachesfirst few weeks
sudden food cravings or aversionsfirst few weeks

Many symptoms that begin soon after conception can continue throughout the pregnancy.

Early pregnancy symptoms can overlap with premenstrual syndrome (PMS), a group of symptoms that can occur in the days and weeks leading to your period.

If you think you may be pregnant, take a home pregnancy test or contact your OB-GYN.

What is the implantation timeline?

In a 2015 article, researchers explain that the window for implantation occurs between days 20 and 24 of your menstrual cycle. This is about 6–10 days after ovulation.

When you get a positive pregnancy test result, your doctor or nurse midwife will calculate a timeline for when your pregnancy began. They will date your pregnancy from the first day of your last period.

According to the NHS, the national health service of the United Kingdom, an approximate implantation timeline follows these steps:

  • Day 1: This is the first day of your last period.
  • Day 14: This is approximately when you ovulate, when an ovary releases an egg.
  • Day 15: Once the ovary releases an egg, it has 12–24 hours for a sperm to fertilize it. If you have had sex with a male in the days leading up to and around ovulation and did not use contraception, a sperm may fertilize the egg. This creates an embryo.
  • Days 20–24: Implantation occurs, which is when the fertilized egg attaches to the lining of the uterus.

At this point, you are pregnant, though it may still be too early for a pregnancy test to produce a positive result.

When to take a pregnancy test

Although many home pregnancy tests claim to detect a pregnancy before a missed period, many healthcare professionals recommend waiting until about the first week after a missed period to take a test.

Home pregnancy tests are almost 99% accurate when you perform them correctly, according to the Office on Women’s Health.

Home pregnancy tests measure the pregnancy hormone hCG in your urine. Your body produces more hCG as the pregnancy develops, so a home pregnancy test will be more accurate over time.

To confirm a pregnancy, contact your OB-GYN about an hCG blood test, which can provide an accurate result earlier than a home test.

When should you contact your doctor?

Not all people experience signs and symptoms of implantation, and the symptoms can vary for those who do.

Contact your OB-GYN or nurse midwife if you have concerns or additional questions about your pregnancy symptoms. They can explain which symptoms are expected during the early stages and through each trimester of pregnancy.

Symptoms of possible complications

While light bleeding and cramps early in pregnancy are common, there are times when bleeding or pain could signal a potential pregnancy complication. This could include miscarriage or an ectopic pregnancy.

Contact your OB-GYN or nurse midwife right away if you experience:

  • bleeding that occurs after the first trimester
  • heavy bleeding that soaks through a pad or tampon in less than 2 hours
  • bleeding that includes large blood clots, the size of a quarter or bigger
  • bleeding that occurs with severe cramping or stabbing pain in your lower abdomen
  • bleeding that occurs with nausea or vomiting
  • significant abdominal or pelvic pain

When in doubt, contact your doctor or nurse midwife about any bleeding or other symptoms that cause you concern.

Other frequently asked questions

These are some other questions people often ask about implantation symptoms.

Can you feel fertilization symptoms before implantation?

No. Before implantation, a fertilized egg moves along the fallopian tube to the uterus. Symptoms such as light bleeding and cramping do not begin until the fertilized egg implants.

How long do you feel implantation?

Symptoms of implantation may last about 1–3 days. However, every person’s experience is different. Some people experience no implantation symptoms.

Do you feel tired during implantation?

During implantation, placental cells begin to produce small amounts of the hormone hCG, and hCG production continues to rise for the first 8–11 weeks of pregnancy.

One of the symptoms of hCG production is fatigue. It usually takes a few weeks for hCG to reach a level that causes fatigue, though, for some people, fatigue begins as early as 1 week after conception.

Summary

Implantation symptoms include light bleeding and mild cramping. Bleeding that occurs with implantation is typically lighter than a usual period.

Other early pregnancy symptoms include a missed period, fatigue, sore breasts, nausea or vomiting, and increased urination.

If you think you may be pregnant, take a home pregnancy test at least one week after the first day of your missed period. Contact your OB-GYN to confirm your result. If you are pregnant, your doctor or nurse midwife will talk you through the next steps and help plan for your prenatal care.

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Medical Reviewer: Sanaz Ghazal, MD, FACOG
Last Review Date: 2022 Aug 12
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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