Pregnancy test accurancy???
 

My wife bought a twin pack of early tests from the pharmacy 2 days ago. She did one in the evening we bought is and the extra line came up very very faint. Apparently this still means positive.

She then took the second one in the morning and the line came up very clearly positive.

Then we bought a digital one yesterday which she used today which should have told her approx which week she is in, it came up negative!!

The first 2 were a slightly cheaper version, Forlan or something was the brand, but the pharmasist assured us its just the same as the clear blue but a cheaper version. Still guaranteed a 99% accuracy.

The digital one was a clear blue, which is also 99%.

If the cheaper one is a 1 in 100 chance for 1 test being wrong, then the chance of 2 in a row being wrong would be 1 in 10000!

Have any other women had this problem? Which do you think is correct? We would really like to know but she cant get an gyno appointment till saturday, getting impatient :confused:

Re: Pregnancy test accurancy???
 

The best way of doing the exam is early in the morning as soon as you wake up, maybe that could be the reason? Still, I'd have a blood test done :msngrin:

Re: Pregnancy test accurancy???
 

I am lead to believe a line is a line and that a pregnancy test can give a false negative but never a false positive

So maybe congratulations are in order?

:)

Re: Pregnancy test accurancy???
 

How long is it since she should have had her period? It might be a bit soon but I echo Angela's advice - the morning is the best time especially if it's very very early in the pregnancy (it actually says that on the pack).

Re: Pregnancy test accurancy???
 

I haven't heard from my pregger friends about having a positive test then a negative test. False positives do happen, but rare I think. Hmm... take another test. Follow the instructions and take one more. If she's had two positives, I'm thinking she's pregnant. FYI, it's best to test in the morning with the first morning pee. The pregnancy hormone is more potent.

Hope you get some happy news. :)

Re: Pregnancy test accurancy???
 

Not an expert here, but I have heard that it is very unlikely that a home pregnancy test would give you a false positive, but they often will show a false negative. In other words, you probably put a baby in her. :D

Re: Pregnancy test accurancy???
 

it was only the first test which was done in the evening, thats why we didnt really take it seriously. I heard that they cant give false positives too, but we are hoping so much that we are paranoid that its a neg.
She will get the blood test on saturday but the waiting will kill us, its like a 5 year old waiting for xmas day.

maybe we will just pick up another couple of tests tonight and hopefully the law of averages will give us the answer.

She would be due her period in the next 4 days, her last period was very short which wasnt normal, she may already have had been pregnant then

Re: Pregnancy test accurancy???
 

There is also something referred to as a chemical pregnancy which may have happened.
It's where conception takes place but implantation doesn't. This can result in a small amount of the Hcg hormone being produced -enough for a faint positive pregnancy test but as the pregnancy does not take, this hormone drops off quickly - thus resulting in a subsequent negative test.

As far as I know, true false positives, where there is really absolutely no Hcg are very very rare/impossible.

I would wait a couple of days, take another test to know for sure. If she's pregnant, it will be clear as the hormones increase exponentially.

Found a link: http://www.chemicalpregnancy.org/

Re: Pregnancy test accurancy???
 

Sounds like it. We pooled together and got you a T-Shart.

http://i13.photobucket.com/albums/a2...sonthemama.jpg


(Congratulations if it really is positive!)

Re: Pregnancy test accurancy???
 

Unless the "2 in a row" were manufactured together, shipped together, stored together before they were finally sold together. ;) Depending what the hypothetical problem is, it could easily could have affected both.

And anyway you know one of these three tests was wrong - so you are already in that 1:100 territory.

I'd say wait until Saturday, and in the meantime try to persuade yourselves it is negative. Fingers crossed that you will be pleasantly surprised!


(The drop-in clinic at the Zurich train station doesn't do blood tests, does it? Your insurance wouldn't pay, but it might be cheaper than running round buying all these pregnancy tests from different pharmacies...)

Re: Pregnancy test accurancy???
 

You are testing very early so its quite normal for some tests to not show a positive

I would keep testing each day and the line should get stronger and stronger each day (but make sure its the morning as others have mentioned)

I know how hard the waiting is and I know haw hard it is to test early but testing early results in what you are experiencing now (nerves and uncertainty)

Good luck

Re: Pregnancy test accurancy???
 

Congrats. I think. Unless something gave false positive reading, meds or illness.

I think the regular pee sticks would read better, but I am no expert. Mechanically, faint line is a faint line, so is the definitely positive line. The digital might have something broken in reading the tests, there is an extra transfer of info which could have been bad.

Pick up another test, just to be sure, and if she has missed one day of her period, those morning pee stick tests should be very accurate.

The digital reading might have been a fluke.

(I didn't buy the tests here. At home it is exactly 13fr cheaper).

Actually, I had a posivite one, then neg, then pos, because they each had a different sensitivity. It didn't matter what part of the day, either, for me. But how sensitive the tests were. I think they only sell the tests with the same sensitivity here. I found it, 25mlU/ml tested more acurrately than tests I had with 45 mlU/ml.

It should be on the test packaging.

Re: Pregnancy test accurancy???
 

If you got two positives, no matter the negative, chances are nearly overwhelmingly good that you're about to be a dad. :) Mazeltov!

The pee stick tests these days are really accurate and sensitive.

Re: Pregnancy test accurancy???
 

I wanted to mention this too but thought it might be too negative...

Many women never even know they have had a chemical as most would never test this early and therefore wouldn't know they had any HCG in their system'

I hope this is not the case for you

Re: Pregnancy test accurancy???
 

Ok I found this, not very conclusive sorry..
Diagnostic Efficiency of Home Pregnancy Test Kits
A Meta-analysis


Lori A. Bastian, MD, MPH; Kavita Nanda, MD, MHS; Vic Hasselblad, PhD; David L. Simel, MD, MHS
Arch Fam Med. 1998;7:465-469

Objective To assess the diagnostic efficiency of home pregnancy test (HPT) kits.

Data Sources A literature search of English-language studies was performed with MEDLINE and a review of bibliographies.
Study Selection Studies were included if HPT kits were compared with a criterion standard (laboratory testing), if they used appropriate controls, and if data were available to determine sensitivity and specificity.
Data Extraction Two investigators independently extracted data, and disagreement was resolved by consensus. Sensitivity, specificity, and an effectiveness score (a measure of the discriminatory power of the test, with higher scores implying greater effectiveness) were calculated.
Data Synthesis Five studies evaluating 16 HPT kits met the inclusion criteria. The range of sensitivities for HPT kits was 0.52 to 1.0. In studies where urine samples obtained by the investigators were tested by volunteers, sensitivity was 0.91 (95% confidence interval [CI], 0.84-0.96). However, the sensitivity was less in studies where subjects were actual patients who performed the test on their own urine samples (sensitivity, 0.75 [95% CI, 0.64-0.85]). The test effectiveness score was 2.75 (95% CI, 2.3-3.2) for studies where subjects were volunteers but deteriorated to 0.82 (95% CI, 0.4-1.2) for studies with actual patients.
Conclusions The diagnostic efficiency of HPT kits is greatly affected by characteristics of the users. Despite the popularity of these kits, the relatively low effectiveness scores of these kits when used by actual patients are of concern. We suggest that manufacturers of HPT kits publish results of trials in actual patients before marketing them to the general public.

Re: Pregnancy test accurancy???
 

the digital one is not that sensitive and you can test only up to 4 days early and even then, according to the information leaflet of Clearblue digital, only "55% of pregnant women received a ‘Pregnant' result 4 days early". So it's most likely false negative, too early to test with the digital one.

Congrats!

Re: Pregnancy test accurancy???
 

As someone else mentioned, you may be better off just going to the Permanence at Basel main station to see a doc. May not be covered by your insurance, but they could sort you out with a quick blood test and put you out of your guessing agony in 5 mins.
Keeping fingers crossed it's a go

Re: Pregnancy test accurancy???
 

Thats some great information! hope its correct

Re: Pregnancy test accurancy???
 

Yeah, I thought twice before posting it, but then figured, it was better to be pleasantly surprised if the next test came up positive than thinking all was well, must just have been a dud test, then getting another negative. At least there is a logical explanation if the next one is negative.

Fingers crossed then next one is positive though of course!

Re: Pregnancy test accurancy???
 

I just contacted permanance zurich, they said they dont do blood tests for pregnancy :(

they gave me a contact called medica in zurich, heading there shortly, will let you all know how it goes, fingers crossed for us !!!!