Positive Pregnancy Test: When And How Early After Implantation?

  • woman-sitting-on-toilet-seat-pregnancy-test-implantation-bleeding

When is the urine hCG test positive after implantation?

A blood pregnancy test is usually positive 3-4 days after implantation and a urine pregnancy hCG test is usually positive several days later or about  4-5 days after implantation.

You want to take a pregnancy test, but you have questions: How long do I have to wait after a missed period before I take a test? How long after implantation can I test? It can be confusing.

A positive pregnancy blood test first happens about 3-4 days after implantation bleeding and about 4-5 days before a missed period. The early urine home positive pregnancy test (HPT) can usually detect pregnancy 6-7 days after implantation. Sometimes it can be as early as 2-3 days before the missed period. Implantation usually happens about 9 days (range 6-12 days) after ovulation, fertiliziation or about 8 days before the next period. 

How early can I take a pregnancy test? 

An early pregnancy test becomes positive only after the fertilized egg has arrived inside the uterus and implanted into the uterus and then sent enough amounts of hCG, human chorionic gonadotropin, the pregnancy hormone, into your blood stream and from there into the urine.

The urine pregnancy test (home pregnancy test or HPT) checks for the presence of the pregnancy hormone hCG in the urine. hCG is made by the implanting blastocyst and first appears in the maternal blood around implantation, on average 9 days (range: 6-12 days) after ovulation. Blood hCG levels then rise rapidly to reach a peak at 7-10 weeks. They decline after that time. 

You can interactively and for free do our online pregnancy test to find out if you are pregnant or not HERE.

With most current pregnancy test kits (sensitivity 25 mIU/ml), hCG can be detected in the urine as early as 3-4 days after implantation, though it often takes longer. If you are pregnant, on the day you miss your period about 74% of HPTs will be positive. So a negative pregnancy test is normal in about 26% of all pregnancies, and you may have to retest until you know the results.
 

A negative HPT result 10+ days after the missed period makes a pregnancy unlikely. With the present generation of test kits, false-positive results due to interfering materials are extremely unlikely. Pregnancy tests have now reached a level of sensitivity and specificity that is unlikely to be surpassed either by better tests or alternative technology. 

Positive pregnancy test results can show up any time before or after a missed period. Read below more about when the pregnancy test result first becomes positive.

The early urine ept HPT pregnancy test result is usually positive within 10-12 days after ovulation which is about 3-4 days after implantation

An early pregnancy test result checks for the presence of the pregnancy hormone hCG human chorionic gonadotropin in the urine. 

hCg is detectable in the blood only after implantation. Implantation, the attachement of the fertilized egg to the uterus, happens on average 7-9 days after ovulation with a range of 6-12 days. You need to find enough hCG in the urine to get a positive pregnancy test, and with most current pregnancy test kits (sensitivity 25 milli-international units per milliliter) the pregnancy hormone hCG can be detected in the urine as early as 3-4 days after implantation (9-15 days after ovulation), though oftentimes it can take longer because the urine may be diluted or there is not enough hCG yet in the urine, or implantation happens later than extected. Our pregnancy calendar will help you calculate the due date and other important dates, and our ovulation calendar will calculate your fertile days.

hCG levels are also higher in women carrying a female fetus when compared to women carrying a male fetus, so it is possible that the pregnancy test becomes positive later in women carrying a male fetus (Read HERE more).

Why does it take sometimes longer for the pregnancy test to become positive?
What makes the pregnancy test become positive?
Here are the expected positive positive home pregnancy tests in women who are pregnant based on a scientific study:

Expected Period (EP)

Expected Menstrual Period How often is the 
Pregnancy Test Positive?
3 Days before Expected Period 51% positive
2 Days before Expected Period 62% positive
1 Day before Expected Period 68% positive
Day of Expected Period 74% positive
1 day after Expected Period 79% positive
2 days after Expected Period 85% positive
3 days after Expected Period 90% positive
7+ days after Expected Period 96% positive
  • About one in two HPTs are expected to be positive 2-3 days before a missed period
  • Three in four HPTs are expected to be positive on the day you miss your period
  • A negative pregnancy test on the day of a missed period is normal in about one in four pregnancies, and within the next 4-5 days most HPTs usually have become positive.
  • A negative HPT result 10+ days after the missed period makes a pregnancy unlikely.

From: Wilcox in JAMA 2001; 286:1759

Positive Blood Pregnancy test 

The blood pregnancy test is usually positive within 3-4 days after implantation or about 9-10 days after fertilization and ovulation. About 5-6 days before a missed period

Positive Urine early home Pregnancy Test (HOME HPT) 

The early positive urine pregnancy test will become positive about 2-3 days after the positive blood test or about the time of a missed period, and sometimes a couple of days before the missed period. About 25% of pregnant women will test positive with the early home pregnancy test about 2 days before a missed period, and about 40% the day before the missed period.

The wide variation of when the urine pregnancy test becomes positive and how early pregnancy can be detected are due to four variables which determine when the home urine pregnancy test becomes positive:

1. Timing of Implantation

A pregnancy test detects the presence of the pregnancy hormone hCG (human chorionic gonadotropin) either in the blood or in the urine only after implantation. Implantation can happen as early as six days and as late as 12 days after fertilization/ovulation. At the time of implantation the placenta starts making the pregnancy hormone hCG, which then enters the blood stream. How early pregnancy can be detected depends on the pregnancy hormone hcG which can be detected in the blood about three to four days after implantation. Urine hCG can be detected about two to three days after blood hCG can first be seen. Detection of hCG depends on timing of implantation, so hCG can normally be detected in the blood between nine and 16 days after ovulation (HPT: 12-19 days after ovulation).

2. Blood hCG Level

There is a wide normal variation of hCG levels, both in the blood and the urine and this wide range changes the diagnosis of how early can pregnancy be detected. If a woman has a normal but low blood hCG levels, then it can take several more days for it to show up on a pregnancy test.

3. Urine hCG level

Urine hCG levels change over the course of the day depending on how much you drink and how diluted or concentrated the urine is. Urine pregnancy testing is best done with more concentrated urine. So how early can pregnancy be detected depends on the urine concentration and the quality of the early pregnancy test. If you drink a lot of fluid, the urine may be too diluted early on in pregnancy to achieve an hCG concentration adequate enough for a positive test.

4. Sensitivity of the Early Urine Home Pregnancy Test

Different pregnancy tests have different sensitivities and that has an impact on how early can pregnancy be detected. The lower the sensitivity, the earlier a pregnancy test becomes positive. Sensitivities are indicated in mIU/mL, the lowest amount of hCG in the urine that tests positive. A sensitivity of 20 mIU/mL requires one-half the hCG level to be positive when compared with a 40 mIU/mL sensitivity level, and it may become positive several days earlier than the pregnancy test with a higher sensitivity. Make sure you read the package of the pregnancy test to determine your pregnancy test's sensitivity.

A positive pregnancy test occurs only after the fertilized egg has implanted into the uterus and sent enough hCG (i.e. the "pregnancy hormone") into your blood stream. So the first positive pregnancy test does not usually happen until a couple of days prior to the next expected period. If it is truly positive then it's highly likely that you are pregnant because false positive pregnancy tests rarely occur.

CALCULATOR: When to take the pregnancy test

 

After ovulation and fertilization the fertilized egg or blastocyst takes 4-5 days to travel through the Fallopian tube towards the uterus and it then usually implants inside the uterus.  Implantation, when the fertilized egg the embryo implants into the endometrium, happens about 9 days after ovulation (range: 6-12 days), and it takes another 3-4 days after implantation (9-10 dpo: days after ovulation) for the blood pregnancy test to first become positive. 

  • Blood Pregnancy Test: If you are pregnant then the blood pregnancy test is usually positive within 3-4 days after implantation or about 9-10 days after fertilization and ovulation.
  • Urine Home Pregnancy Test (HPT): The urine pregnancy test will usually not become positive in most women until a missed period or about a week after implantation. The urine test is usually positive at a missed period, but only about 25% of pregnant women will test positive with the HPT 2 days before a missed period, and about 40% the day before the missed period. On average, a pregnancy test will be positive 13-14 days after ovulation and fertilization, or about the time you expect your menstrual period. 

The amount of time it takes for a pregnancy to be detected and the wide variation of time it takes for a urine pregnancy test to become positive is due to five variables:

  1. Timing of ovulation
  2. Timing of implantation
  3. Blood hCG levels
  4. A woman's weight (being overweight lowers the hCG)
  5. Urine hCG level (e.g. how concentrated or diluted the urine is)
  6. Sensitivity of the pregnancy test 

1. Timing/Day of Ovulation: A pregnancy test depends on the day of implantation and the urine pregnancy test is usually positive 4-5 days after implantation. However, the day of ovulation is important too, as implantation can only happen if ovulation took place and the egg was fertilized. Therefore, if your day of ovulation was later than you thought, implantation and subsequently the positive pregnancy test will also be delayed. This is why it is really important to keep track of your ovulation day (OD) so you can start counting the days to implantation and eventually the positive pregnancy test. 

2. Timing of Implantation: A pregnancy test detects the presence of the pregnancy hormone hCG (human chorionic gonadotropin) either in the blood or in the urine. The hCG in the urine comes from the hCG in the blood after being filtered through the kidney. After ovulation, the egg gets fertilized and travels through the fallopian tube toward the uterus. This journey takes about a week on average. Implantation, the attachment of the fertilized egg to the lining of the uterus, occurs on average about a week or so after ovulation/fertilization, but it can happen as early as six days and as late as 12 days after fertilization/ovulation. At the time of implantation, the placenta starts making the pregnancy hormone hCG, which then enters the blood stream. How early a pregnancy can be detected depends on the pregnancy hormone hcG, which can be detected in the blood about three to four days after implantation. Urine hCG can be detected about two to three days after the blood hCG can first be seen. Detection of hCG depends on timing of implantation, so hCG can normally be detected in the blood between nine and 16 days after ovulation (HPT: 12-19 days after ovulation).

3. Blood hCG Level: There is a wide variation of "normal" hCG levels, both in the blood and the urine. This wide range changes the diagnosis of how early a pregnancy can be detected. If a woman has low blood hCG levels, for example, it can take several more days for it to show up on a pregnancy test. If a woman is overweight, with a high BMI, then the blood hCG levels are often lower.

4. Urine hCG Level: Urine hCG levels change over the course of the day depending on how much you drink and how diluted or concentrated the urine is. The time it takes for a pregnancy to be detected depends on the urine concentration. If you drink a lot of fluid, the urine may be too diluted early to achieve an hCG concentration adequate enough for a positive test. Urine pregnancy testing is best done with more concentrated urine.

5. Sensitivity of Urine Home Pregnancy Test: Different pregnancy tests have different sensitivities, which affects how soon a pregnancy can be detected. The lower the sensitivity, the earlier a pregnancy test becomes positive. Sensitivities are indicated in mIU/mL, the lowest amount of hCG in the urine that tests positive. A sensitivity of 20 mIU/mL requires one-half the amount of hCG to be positive as a test with a 40 mIU/mL sensitivity level; it may become positive several days earlier than the pregnancy test with a higher sensitivity. Make sure you read the package of the pregnancy test to determine your pregnancy test's sensitivity.

Spotting and positive pregnancy test

Some bleeding early in pregnancy, maybe some drops or brown discharge, is also called 'spotting.' Spotting happens in 20-30% of pregnant women, usually around the time of the missed period, and most women with spotting continue and deliver a healthy baby. Implantation bleeding usually happens 5-6 days after ovulation. If your pregnancy test is positive, then implantation happened at least 4-5 days ago and it's unlikely that the spotting represents implantation bleeding. If you have a positive HPT and you experience spotting with pain and cramping, you should contact your doctor right away. Your doctor can check the viability of your pregnancy by doing two hCG blood tests 48-72 hours apart. If the hCG levels more than double, then you have a viable pregnancy.