What to Expect with a Pregnancy Blood Test


Couples who are trying to get pregnant are are frequently confused about how pregnancy blood tests are performed and what they mean.

There are two main types of pregnancy tests – blood tests and urine tests. Both tests detect pregnancy by noticing a hormone called human chorionic gonadotropin (hCG) which is also commonly called the ‘pregnancy hormone’ because it is created soon after the embryo has attached itself to the uterine lining in the womb. This hormone is easily measurable in the blood and urine within 10 days of fertilization, or 1 to 2 days after implantation has occured.


There are two types of blood tests:

quantitative blood test measures the exact amount of hCG in the blood. Based on the results, the age of the fetus can be approximated. Unlike the qualitative test, this test can tell if the pregnancy is developing normally.

A qualitative hCG blood test gives a simple yes or no answer to whether you are pregnant or not by simply detecting the presence of hCG in the blood. If you have not yet taken a home pregnancy test, then a qualitative blood test is usually recommended before a quantitative blood test.


How is the blood test conducted?

As with anything that relates to blood, it has to be drawn, before it can be analyzed. Although the blood is usually withdrawn from the forearm, if your veins like to play hide and seek, then the blood will be drawn from one of the veins on the back of your hand instead. A technician or nurse will first clean the area with an antiseptic, before applying a tourniquet to your arm to enlarge the vein. Very gently, a delicate needle is inserted into the vein, and then the nurse will remove the tourniquet. A syringe or vial is used to collect the blood. This sample will then be sent to the laboratory to determine how much hCG is in a woman’s blood. Each lab has its own turnaround time, so be sure to check with the nurse as to when the results can be expected.

If you live in a city, you might be able to go to a hospital, which is faster concerning lab results, should you be anxious to know what your results are.


Understanding the results

For basic qualitative blood tests, if the amount of hCG is over a certain limit it will come up as positive, especially if the level is at least 5 mIU hCG. This is most easily detected shortly after conception has taken place.

With the more complex, quantitative, pregnancy tests that relate to blood, the exact amount of the hormone in the blood is measured. A medical practitioner will then be able to determine how far along you are. This test will be repeated throughout the pregnancy to make sure that everything is progressing, as it should. During the first four weeks of your pregnancy, your hCG levels should double every two days. However, by 6 to 7 weeks gestation, your hCG levels may take as long as 3 1/2 days to actually double. If your hCG levels do not double properly, your pregnancy by at risk and your doctor will discuss any concerns with you.


Blood tests are not infallible as everything is prey to human error. If one is not sure about the result, have a second test done. Sometimes this occurs if the blood test is conducted too early.



  • kira

    my blood work came back as below 2 what does that mean ?

    • Unfortunately that falls below the level where you can be considered pregnant. 10 miU of hcg is considered positive. If you got a positive pregnancy test, it could mean that you had an early miscarriage.

      • Cassie TracesMomma

        Actually it is 5miu that considers you pregnant.

        • Rebecca

          I’m so confused, I got level 3 on mine last Monday and they said it’s not positive or negative and needs to be retaken in a week????

          • I’m not sure what that means. But it could be that the hcg level is right at the positive mark and still very low. Going back next week will give your body time to create more hcg and result in a higher “definitely pregnant” level.

          • Deanna Robinson

            I took a blood pregnancy test two weeks ago and my hcg was 2.00 and then got another one done today and my hcg level was 3.25. Could I be pregnant?

          • goutham sai

            Doc please help me….and my partner did genital rubbing but no intercourse took place and no leak also…but she got periods for 4 months can she be pregnant?
            Please help

          • Deanna Robinson

            Did you retake a pregnancy test?

  • Mel

    I’m seven days from conceiving but I had cramping and spoting went to hospital but the blood wrk says I lost baby I feel pregrant still

  • Sa

    Just had a baby four months ago. I had a regular period after that. I had intercourse once since giving birth. However it will be two months since I’ve had my period. I’ve taken four urine test and one blood test. All are negative but I still haven’t received my period. Is this normal?

  • gayathri sreenath.

    I received message from nhs. (Ie) I want to call gp for discussion. What is the meaning of this?

  • Jennifer

    Many prostorn is high and I have sign of pregnant but the blood test was negative

  • Jennifer

    Many prostorn is high and I have sign of pregnant but the blood test was negative

  • samantha

    I went to hospital BC I was dehydrated and my blood pregnancy test was a 4.6 and said I was negative I Aldo took 3 at home test and they were a faint positive. So I’m not sure if I’m a couple days or what but every time I had a test done it was a 4.0 which means absolutely not pregnant but this time was a lot higher I just wish a doc would describe to me

    • You should take a pregnancy test tomorrow morning with your first morning urine to see if the test shows up darker. It could be that it is still very early in your pregnancy if you are pregnant.

  • gina

    Would you no of you had an early miscarriage if you have no cramping and your hcg is 11

    • Did your period arrive? If you are bleeding like a period and you have an hcg of 11 there is a chance that you are experiencing a miscarriage. Having said that, you could also be experiencing early pregnancy bleeding. You will need another blood test to see if the hcg level goes up or down to confirm what is actually occurring .

  • tamara

    I had my last period at the end of March (this is what i recall). Home urine tested positive.ultrasound shows only my 4cm fibroid. No gestational sac can be seen.
    Quantitative blood test came back positive with a figure of 498. I have been asked to do another blood. Im confused because i have miscarried before. I have had no serious bleeding. Only brown spotting on two days.
    going for a transviginal Scan tommorow. Really worried about what all this could mean.Very Confused and worried.

  • Kira Jones

    My bloods came back at 291. What does that mean?

  • Shanice

    I done pregnancy test but that came back negative but had blood done and got pregnancy hormones in my blood what does this mean?

  • Elizabeth

    My blood test was a 7 what does that really mean. Could i be preggo or not?

  • Kell

    Hi. I am nine days late. Yesterday i went to my family doctor and had a blood test. The result for HCG was 7. What does this mean?

  • Tiona Rankins

    Hi.. I just found out I was pregnant June 22 n I went to the doctor cuz I started spotting n they took blood work.. I found out today that my levels BHCG was 44.3 n the other one was 72 BHCG 15.3.. This my first child n I’m trying keep it.. Please tell me what do this mean..

  • Jasmine

    Okay so this is what is going on! I am 3 days late for my period. I feel pregnant. I have gotten super faint positives on FRER but only after the time window when it completely dries. Negative on all other kinds. I have a lot of white and clear cervical mucus, my boobs are super sensitive. I get cramps but no period. I am going in for a blood test tomorrow. Is it possible for it to come back positive when I have had negative home pregnancy tests?

Last modified: May 7, 2014