Blood pregnancy test is one of two options women have when wanting to know if they are pregnant or not. Urine pregnancy test, which can be bought at almost any drug store, is another option. Between the two, urine test is the go-to method for most women, but doing a blood test is also a good option.
Urine pregnancy tests are pretty good and accurate, and so a lot of the times using them are good enough for determining if one is pregnant or not. However, there are times when a blood test may be necessary.
There are two types of blood pregnancy tests: qualitative and quantitative.
The qualitative hCG test is similar to the urine pregnancy test, in that, it gives a “Yes” or “No” or “Positive” or “Negative” answer. A blood test can be done to find out if you are pregnant, in place of a urine pregnancy test. It is more sensitive than the urine test since it can detect hCG levels much earlier, 6 to 8 days after conception.
| Test | Result | Meaning | Interpretation |
| Qualitative Blood Test | Dark line, faint Line | Positive | Pregnant |
| No line | Negative | Not Pregnant |
If you want to know early on if you are pregnant or not, doing the blood test is the better option. It is very accurate and reliable, so, if you do it, there would be no need to do a urine pregnancy test. However, it is possible to do a urine test first and then do a blood test after.
Sometimes, women will do a urine test but based on the result they get, they will come to the lab to do a blood test. The blood test can detect lower levels of hCG in the blood, as well as, it is less prone to false negatives. So, for example, if a woman thinks she’s pregnant but the urine test showed negative, she may come to the lab to do a blood test. Also, a blood test may be used as a way of confirming a pregnancy or not.
The quantitative blood test is different from the qualitative blood test. It does more than give a positive or negative answer and more than just say you are pregnant. It gives a numerical value which doctors can use to determine several things like, if you are pregnant, the stage of your pregnancy, as well as if you are having problems.
The quantitative blood test is generally not used to find out if you are pregnant only, though it can be. The qualitative or urine pregnancy test is used for that purpose. The quantitative blood test is much more expensive than the qualitative or urine pregnancy test, so using it to determine if you are pregnant is not necessary, since the other two can tell you that accurately.
| Test | Result | Meaning | Interpretation |
| Quantitative Blood Test | <5 mIU/mL | Negative | Not pregnant |
| >25 mIU/mL | Positive | Pregnant | |
| between 6 and 24 mIU/mL | Grey area | May need to be rested to see if levels rise to confirm a pregnancy |
Why the Quantitative Blood Test is Performed
Your doctor may request that you do a quantitative blood test because it can help determine the age of the fetus, assist in the diagnosis of abnormal pregnancies, such as ectopic pregnancies, molar pregnancies, and possible miscarriages. It can also be used as part of a screening test for Down syndrome.
Below is a table showing hCG levels in weeks (since last menstrual period) during pregnancy. This table is sort of a guideline as the numbers can change from women to women and the ranges may vary slightly among different laboratories.
Talk to your doctor or health care provider about the meaning of your specific test result.
| Number of Weeks | hCG levels |
| 3 | 5 – 50 mIU/mL |
| 4 | 5 – 426 mIU/mL |
| 5 | 18 – 7,340 mIU/mL |
| 6 | 1, 080 – 56, 500 mIU/mL |
| 7-8 | 7, 650 – 229, 000 mIU/mL |
| 9-12 | 25, 700 – 288, 000 mIU/mL |
| 13-16 | 13, 300 – 254, 000 mIU/mL |
| 17-24 | 4, 060 – 165, 400 mIU/mL |
| 25-40 | 3, 640 – 117, 000 mIU/mL |
Notice that in the first trimester hCG levels rise and afterwards decline.
When to do a Blood Pregnancy Test
The qualitative blood test can be done 6 to 8 days after conception if you decide to do it. The urine pregnancy test is more commonly done than the blood test, but doing the blood test is totally ok. Both are qualitative, in that, they give a negative or positive result.
I think the blood test may be more expensive than the urine test but it’s definitely an option. It is less prone to errors, and while you may do a urine test multiple times, one attempt at the blood test is usually the most you will do.
The quantitative blood test is requested by your doctor. After examining you, your doctor will decide whether to send you to do one. Your doctor may send you to do a qualitative blood test too, but it is one you can do without the request of your doctor, if you want.
With the blood test, you will have to be pricked with a needle. A phlebotomist will insert a needle into one of the veins in your arm and draw some blood. That’s the only downside to blood pregnancy test. Unlike the urine test, no blood is drawn.
Can a Blood Pregnancy Test be Wrong?
It is possible for either a qualitative or quantitative blood test to be wrong but it is not common. These tests are very accurate and reliable. There can be some issues with the kits or the equipment which can result in erroneous results but those are rare.
It is possible for an error to occur in the lab but those are usually rare too. If you think your result may be wrong, talk with the lab or your doctor. The test can be repeated or other tests can be done.
If the test is done too early, it can turn out to be negative. Make sure you have waited long enough before testing. The test can begin to detect hCG levels at around 6 to 8 days after conception but sometimes it can take longer depending on when ovulation started or implantation occurred.