false negative bloode test but positive urine test

kcave21 · October 2014

okay so just wanted to know if anyone has gone through this...

(we have been trying for 5 months now)

I missed my period on tuesday (first day of missed period) so I decided to go for it and take a test. I decided on clear blue pregnancy test (the ones that tell you how far along you are). The first one came out positive so I took another to make sure and also positive, saying I was 1-2 weeks pregnant on both. So wednesday I went in told them what happened so I can go ahead and get blood work for my referral so I can go see my OB/GYN. well today they called me and said it came back Negative...and I asked her if she was sure...and proceeded to explain I am now 4 days late on my period and had 2 positive at home test...so she told the dr again and the dr wants me to come back in to see their OB/GYN and see what is going on.

so my question is...can there be a false negative on a blood test and has this happened to anyone out there? If so, what happened...

Also, I know not to listen to Dr. Google but all the articles I have read said you have to be at least 5 weeks for the HCg to be high enough to come back positive? anyone know if this is true at all?

medical disclaimer noted***

katie0919 · October 2014

You do not have to be 5 weeks for HCG to come back positive. I got pregnant in August and my beta at just 11 days past ovulation was 21. I had a positive in March and my beta blood level was only 11, I started bleeding the next day and had a negative pregnancy test.

Like PP said, it sounds like a chemical pregnancy. Have you taken another at-home pregnancy test to see if it is still positive?

Joy2611 said! I had no idea there was also just a 'qualitative' beta test. You learn something new everyday!

kcave21 · October 2014

Joy2611 said:

Was it a quantitative blood test or a qualitative one?

Quantitative will report the actual beta number (like 5, 10 or 22). A qualitative test will be a threshold value (something like 25) and if you are below the threshold, you are said to be not pregnant.

I'd call and ask for what the actual beta value was.

I'd also pee on another test in a few days to see if it is still positive and ask for another beta draw.

Blood draws are not standard with confirming pregnancies (pee tests are good unless you have a history of problems), but since you're in this blood test fiasco all ready, you might as well see it through.

I am guessing a qualitative test considering she told me I was below at 25? I am going in today..to see the ob/gyn just not sure what they are going to do..I am assuming it is to early for an ultrasound?

kcave21 · October 2014

katie0919 said:

You do not have to be 5 weeks for HCG to come back positive. I got pregnant in August and my beta at just 11 days past ovulation was 21. I had a positive in March and my beta blood level was only 11, I started bleeding the next day and had a negative pregnancy test.

Like PP said, it sounds like a chemical pregnancy. Have you taken another at-home pregnancy test to see if it is still positive?

Joy2611 said! I had no idea there was also just a 'qualitative' beta test. You learn something new everyday!

yes I am not sure the difference btw either test?! I haven't taken another at home test yet? do you think I should?

I am on my second baby (hopefully) and I never got a false positive before and with my first one I think I took 14 neg the first month (I was crazy) and all negative and then a month later after trying I got a positive and took 3 more the be sure and all positive...so I have never had a history of false positive. just hoping when I go in today at 1:30 I will find out everything I need to know...What are some of the questions you all would ask?

divinemsbee · October 2014

I don't think any of the results are so much 'false' as you are bound by whatever the parameters of the tests you're taking are. For example, in my clinic, if your blood hCG level is below 25, you would be considered 'not pregnant' if they just ran a qualitative test. Meaning that you could still be 'pregnant' just not pregnant enough to yet reach their threshold. However, if they run a quantitative test, then they can see whatever number they want (I've had them as low as 5). Which they can use to determine whether your numbers are going up or down more precisely. What they want to see in early pregnancy is a 48-72 hour doubling time.

If your clinic is saying that your numbers are below 25, that doesn't necessarily mean they won't get higher, but it means that you don't yet meet the threshold at which their test will measure you as pregnant. I know with some offices and anything under 50 won't turn their qualitative tests. This is complicated by the fact that at-home urine tests have gotten really sensitive, so they can often pick up pregnancy before some offices' qualitative blood tests would read as pregnant.

What I would do if I were you would be what Joy said. Pee on another test in the next few days and see if you turn it. If you do, then talk to your doctor about getting a quantitative test, meaning they you would get the exact numbers. And it's possible that your levels have risen a lot over just a few days. Then get a 2 day beta run (which is probably what your doc would do anyway, it's what mine would do). That may give you a better idea of what's going on. As PP have said, it could be a sign of a chemical pregnancy, in which case I am very sorry.

kcave21 · October 2014

I just took another test before I went to the dr office and it also came back positive. .. (3rd test...different box) but still clear blue...I see the dr in 15min. Anxious to see what info I get

nursej519 · October 2014

Your problem is false positives not false negatives. Clear blue, or any test with blue dye, has a high false positive rate. Google it. Pink dye brands are much better and by far more reliable.

kcave21 · October 2014

dr. made a mistake and read the wrong blood work to me...my number is actually 196 instead of LESS THAN 2. They read my blood work from November 2013 instead of October 2014

IM PREGNANT!!!

divinemsbee · October 2014

Congrats to you, I'm glad that the tests all got sorted out! I'm sure that was scary, and hope that the rest of your pregnancy goes well.

kcave21 · October 2014

divinemsbee said:

Congrats to you, I'm glad that the tests all got sorted out! I'm sure that was scary, and hope that the rest of your pregnancy goes well.

thanks so much!!! me too

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