Is Blood Testing for Pregnancy Reliable? Your Options

Is blood testing for pregnancy accurate?

Last month, my period started on February 7, but this month it is late.
After a week, I bought a pregnancy test and tested four or five times, all showing one line.
I then went to see a doctor who took an X-ray but didn't see anything, and prescribed me medication to induce my period.
If my period doesn't come after taking the medication, what is the likelihood of being pregnant? Also, how reliable is a blood test for pregnancy?

Lin Lin, 10~19 year old female. Ask Date: 2017/03/20

Dr. Huang Jianzhong reply Obstetrics and Gynecology

Last month, my period started on February 7, but this month it is late.
After a week, I bought a pregnancy test and tested four to five times, all showing one line.
I then went to see a doctor who took an X-ray but didn't see anything and prescribed me medication to induce my period.

1.
If my period does not come after taking the medication, is the chance of being pregnant high?
Answer: The chance of being pregnant is low.

2.
Is the chance of pregnancy confirmed by a blood test high?
Answer: The chance of pregnancy confirmed by a blood test is low.

P.S.
It is recommended to refer to the National Health Administration's "Sexual Health e-Learning" or the Society of Obstetrics and Gynecology's "Adolescent Contraceptive Guidance" at http://goo.gl/dc6PfW.

Reply Date: 2017/03/20

More Info

When it comes to determining pregnancy, blood testing is generally considered one of the most reliable methods available. Blood tests for pregnancy primarily measure the levels of human chorionic gonadotropin (hCG), a hormone produced shortly after a fertilized egg attaches to the uterine lining. This hormone can be detected in the blood as early as six to eight days after conception, making blood tests more sensitive than home urine pregnancy tests, which typically require a missed period for accurate results.

In your case, since you mentioned that your last menstrual period was on February 7 and that your period is now late, it is indeed possible that you could be pregnant. However, the fact that you have taken multiple home pregnancy tests and all have shown a negative result (one line) suggests that you may not be pregnant. Home pregnancy tests are generally accurate, especially when used correctly and after a missed period. However, false negatives can occur, particularly if the test is taken too early or if the urine is diluted.

Regarding the blood test, it is more sensitive and can detect lower levels of hCG than urine tests. If you are still experiencing a missed period after taking the medication prescribed by your doctor to induce menstruation, it would be advisable to follow up with a healthcare provider for a blood test. This test can confirm whether or not you are pregnant with a high degree of accuracy.

If you take the medication to induce your period and it does not come, the likelihood of being pregnant increases, especially if you have had unprotected intercourse around your ovulation period. However, it is essential to understand that hormonal imbalances or other medical conditions can also cause a missed period, so it is crucial to consult with your healthcare provider for further evaluation.

In summary, blood testing for pregnancy is highly reliable and can provide clarity in situations where home tests yield ambiguous results. If you have concerns about your menstrual cycle or potential pregnancy, it is best to consult with your healthcare provider for appropriate testing and guidance. They can help determine the next steps based on your individual situation, including whether further testing or treatment is necessary.

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