Blood Drug Testing

How accurate are blood pregnancy test?

The reason I ask is because I can't remember accurate when my last period was. My sonogram due date says I am due on March 5, 2008 and that would put my LMP starting on May 30. I went to the ER and had a blood pregnancy test done on June 3, 2007 and it was negative. I had sex on June 13 and June 17 with my boyfriend. On July 16 I took a preg test and it was positive. I just wanted some feedback. Thanks-

Public Comments

1. pretty darn.
2. positives are always accurate, negatives can be faulty.
3. Next to popping it out, 100%.
4. as far as I know they are pretty accurate... as long as the hormone is in your body
5. Blood pregancy tests are a hundread percent accurate, but it takes ten days before they can find the hormone in your body.
6. Anything with blood always a small margin of error however its less than 3% error. They are over 97% accurate. You were probally not pregnant when you had the blood test done and are now. Go and have it again perhaps.
7. On June 3rd, you weren't pregnant yet. You got pregnant about two weeks after the first day of your last period, so somewhere around the middle of June was conception. The pregnancy test in July was about two weeks after you became pregnant, so it would show up as positive.
8. I DRAW BLOOD......MORE ACCURATE THAN A URINE PREG....BETA HCG (QUANT) WILL GIVE YOU HOW FAR ALONG YOUR ARE....AND BETA HCG (QUAL) WILL ONLY GIVE YOU A YES OR A NO, THAT YOUR PREG...
9. YOu have conflicting information. I think you should see a doctor. Blood work is more sensitive than urine tests. But sonograms are the most accurate. If you have the sonogram and were due in march, and then a month later you have negative blood work it sounds like you miscarried and then got pregnant again recently. Either that or the ER botched the blood work. Either way it is a mess, you need to be seen.
10. it actually takes 5 days (about) after your missed period for your body to start producing the hormone that the test reads... so you may have been pregnant when you went to the ER... or you could have gotten pregnant on the 13 or 17th. You trying to figure out who the father is? if it is really that close you may have to get a paternity test done...
11. Blood pregnancy test are very accurate. I cant explain what happened with that ER blood test, but if I were you, I would go to my OB/GYn explain what happened and have them repeat the blood work and do an ultrasound. How many weeks are you? after 12 weeks, HCG starts to decline in your body as the baby begins to rely on the placenta for its nourishment and blood supply. Its possible that the ER was expecting your numbers to fall within a certain range for your gestational stage and if you've already begun declining HCG levels they considered your test negative. That really is an odd situation and I would go back to my OB/GYn and tell them you need to see any Dr in the practice to do a scan and repeat blood work to make sure that all is OK with your baby. Good luck ..let us know what happens..
12. If your hpt showed positive on June 16, then take a blood test now and it should show positive. Believe me hcg blood test are 99.9% accurate when detecting the hormone. What happen is that you took the blood test WAY too EARLY. Cause If your LMP was May 30 you should have ovulated between June 13 to 17. So if your HPT was done on July 16 that means you were possible to test positive like two weeks earlier. If you are 28 day cycle you ovulate 14 days from the first day of your last period. It was impossible you could have gotten a positive three during your period. Hope it helps!! CONGRATULATIONS!!
13. Blood test's are the most accurate test there is. They will show a positive result within a few days after implantation. When you tested the first time it may have been too early. I would go by your sonogram because they are giving you that date to match up with the baby's development. Congrats!!
14. THEY ARE PRETTY ACCURATE. SOMETIMES WHEN YOUR PREGNANT IT DOESNT SHOW UP RIGHT AWAY.