This is supposed to never happen... so how did it?

July 30, 2006 10:14 PM

So, on July 5th I had a positive pregnancy test. It was two nice dark lines that appeared right away. (I even scanned it.) Friday, I went to my first prenatal appointment, where on the ultrasound they found... nothing. Just got the blood test results back, and they are negative for pregnancy. I'll probably get a call from the nurse practitioner tomorrow, but she's not likely to be helpful, since

I had to explain to her what an ACE inhibitor was (why in the hell am I having to explain drugs to my health care provider? Should this not be the other way around?), and the only explanation she could offer was that "oh, the tests are just wrong sometimes." However, from what I've researched, the tests AREN'T wrong the vast majority of the time. "False negatives" happen (when you test too soon, and turn out to be actually pregnant later) and some people stare at where the line is supposed to be until they think they can see it, but this isn't the case here. Sometimes you can get a positive and then get your period-- this is generally very early miscarriage, not a true false positive. This case, where the HPT is definitely positive, and the blood test is negative, and there is no subsequent miscarriage, is supposed to be exceedingly rare. I haven't had a period in the meantime. There is no real action I can take here, but I just would like to understand how this could happen.

Everything I could think of that might remotely have a bearing on this:
I have PCOS, diabetes, hypothyroidism, and hypertriglyceridemia. At the time of the test I was taking: Metformin, levothyroxine and Cozaar by prescription, and OTC prenatal vitamins, calcium citrate, CoQ10, and Estroven (or the Sam's Club knock-off). As far as I know, none of these contain hCG (the hormone that pregnancy tests detect). OTC items CAN'T contain hCG, right? It's prescription only. After the positive test, I stopped taking the Cozaar and Estroven, and added an additional .8 mg of folic acid. I'm just incredibly boggled by this, and unlikely to get a good answer out of Kaiser.

posted by Shoeburyness to health (19 comments total)

On the other hand, it's not unheard of to spontaneously abort at early stages, nor for the embryo to be reabsorbed.
posted by Kickstart70 at 10:25 PM on July 30, 2006

What brand did you use? They vary.
posted by Zed_Lopez at 10:27 PM on July 30, 2006

The tests aren't wrong the vast majority of the time, but they can be wrong. Wikipedia says:

False positive results can result from diseases like choriocarcinomas, IgA deficiencies, heterophile antibodies, enterocystoplasties, gestational trophoblastic diseases (GTD), gestational trophoblastic neoplasms (GTN), and testicular germ cell malignancies. Also, many home pregnancy tests show a positive or unclear result when read well after the suggested 3-5 minute window, independent of an actual pregnancy; this type of false positive is also known as an evaporation line. Additionally anyone who has been given an hCG injection would also give a false positive.

These guys say it could be as simple as a faulty strip. This site has more info about false positives - they just happen.

If your blood work is negative, that's pretty conclusive. I'm sorry.
posted by obiwanwasabi at 10:31 PM on July 30, 2006

Am I tripping out? That looks like one of the "+/-" tests, where a positive result would actually look like a plus sign. I don't see a plus sign. Sorry to question you - I know this sounds really obvious - but are you reading the test correctly? Feel free to call me an idiot.
posted by peep at 10:38 PM on July 30, 2006

Shoeburyness, I'm sorry. It is heartbreaking to see that empty ultrasound screen. Please take good care of yourself.

Here is my thought: perhaps you had an early miscarriage, unbeknowst to you, which resulted in what you thought was your last menstrual period. The home pregnancy test showed a line from residual pregnancy hormones from the earlier pregnancy/miscarriage. As that miscarriage resolved, your hcg went to zero, and the latest blood test (I guess July 28?) shows a negative.

When was your last menstrual period? How far along did you expect to be?
posted by crazycanuck at 10:48 PM on July 30, 2006 [1 favorite]

I don't know if the information is helpful, but the PDR for that particular test (based on clues from your image) says that two parallel lines, one in each window, indicate that you are pregnant, as follows:



Your test does not show two parallel lines. Like peep, please feel free to call me an idiot if I'm way off base here.
posted by RichardP at 11:24 PM on July 30, 2006

Could it have been a chemical pregnancy? I know you haven't had a period since the positive test, but I also don't know anything about your cycle or how common a chemical pregnancy is without a subsequent period. Given that you have PCOS I will hazard a guess that your menstrual cycle may be irregular, and this perhaps could explain the positive HPT but negative blood test results without a period.

I'm really sorry about this. I hope you can find some answers.
posted by Felicity Rilke at 11:28 PM on July 30, 2006

Isn't this just the lottery paradox in reverse? Just because a probability is very small does not mean it cannot occur. The odds of winning the lottery are so remote that you have to be an innumerate fool to buy a ticket and expect to win, and yet somebody ends up winning every couple of months, just because so many people play. If you figured out how many million pregnancy tests are sold per year I'd be willing to bet that no matter how small the probability of a true false positive, the number will be more than zero.
posted by Rhomboid at 12:00 AM on July 31, 2006

On the other hand, it's not unheard of to spontaneously abort at early stages, nor for the embryo to be reabsorbed.

Really? Of course, I knew of spontaneous abortion, but I didn't think humans could reabsorb the embryo. I thought that was a rodent thing.

According to the box, that is a positive test. The outer casing is identical to the +/- tests, so I can see where the confusion arises. (It's the E.P.T. brand, one of the more expensive tests on the market. Gee, next time I'll just go with the dollar store crap.) The insides of the test are different, though. The +/- tests have up to two solid lines in the test window, and one solid line in the control window. My test has a dashed line in the test window, and a solid line in the control window. I had used the other test in this pack a month previously, and got a negative-- which was no dashed line in the test window, one solid line in the control window. I read that the +/- tests were causing confusion because dye from the line that always appeared would sometimes wick up the other line, causing people to read it as positive when it wasn't. I haven't seem the +/- tests in our local stores for a while. This one is two lines pregnant, one line not pregnant.

So far, Crazycanuck's scenario seems most likely. I did have a very, very light period a few days before the test, but then again, I had the exact same thing before I discovered I was pregnant with my 2 year-old, so it didn't seem odd to me to be pregnant after an exceedingly light period.
posted by Shoeburyness at 12:03 AM on July 31, 2006

On further inspection, it seems like there are +/- tests with the dashed line, as well. But I doubt I would have missed this, since they usually have a big blurb on the front of the box about it being + or -. It's hard to tell from the on-line pharmacy pictures, but there appear to be two different kind of EPT tests, +/- tests and the other ones. Unless I'm just going insane, I had one of the other ones.
posted by Shoeburyness at 12:26 AM on July 31, 2006

Shoeburyness, was it a Pfizer e.p.t test? As far as I've been able to determine, Pfizer currently only markets two kinds: a +/- test and a digital test. The picture of a negative result in the directions for their +/- test (pdf) look an awful lot like your scanned image. In any case, you certainly sound sane to me.
posted by RichardP at 12:44 AM on July 31, 2006

Oops, the PDF link in my previous comment should have gone here.
posted by RichardP at 12:47 AM on July 31, 2006

Argh, I think I'm going insane. The PDF link should be to here.
posted by RichardP at 12:49 AM on July 31, 2006

I think that you'll have a definitive answer pretty soon. If you start missing periods, that'll tell you. If you have a period, that will, too.

Good luck!
posted by Steven C. Den Beste at 1:10 AM on July 31, 2006

It does. But I'd be prepared to swear that there wasn't any mention of a +/- on the box. I wonder if I could have gotten a newer test in an older box? Not like the boxes are ever sealed. In any case, I feel like a huge idiot.
posted by Shoeburyness at 1:11 AM on July 31, 2006

If you're attempting to get pregnant, you can buy a large number of dip strips from many mail order sources. These are less user-friendly than the high-tech ones sold in drugstores, but just as effective and much much cheaper. (20 of the dip strips for the price of one drug store test.) So in the future you can do the test every day without breaking the bank.

It is quite common for so-called chemical pregnancies to occur. One has a positive HCG test, briefly, but something goes wrong; the embryo is defective and doesn't make it.
posted by jellicle at 7:50 AM on July 31, 2006

Sounds like you're having a Kill Bill moment with the pregnancy test. I helped a freaked-out friend take a pregnancy test once, and I made sure to buy the one that read "pregnant" or "not pregnant" (the latter, luckily) cuz I didn't want to deal with all the damn blue lines.
posted by radioamy at 8:46 AM on July 31, 2006

Trust me, you are not an idiot. I'll say no more.
posted by ewkpates at 9:45 AM on July 31, 2006

I've had multiple early miscarriages, and I remember how hard it was figuring out all the back and forth of tests. I'm really really sensitive to hormones so I'd show symptoms fast, but short of having blood drawn every damn month, by the fourth or fifth, I stopped going to the doctor to check and just dealt with it myself because I was sick of arguing with ambiguous tests (several were confirmed because they lasted longer). What I'm trying clumsily to say is trust your body if something happened, but you may need to accept that what happened didn't last long enough to show on paper/facts.

Did you have an abdominal or vaginal ultrasound? If it happens again, and you're getting mixed results from blood tests and urine tests, ask for a vaginal ultrasound. It's partly psychological - it's a lot easier to handle seeing or not seeing than a test result, and it's also easier to date the embryo or spot differences. They take ten minutes, and are slightly uncomfortable (full bladder like an abdominal). Early on vaginal ultrasounds are more useful.

It really, really varies. Some people bleed a lot, some people don't at all. It might help you to read up on early miscarriages, or it might depress you more. But they are a lot more common than most people realise. And when you're trying to get pregnant, they are emotionally painful but invisible.

Also, most doctors will *not* consider early miscarriages an issue until you've had at least three, because they are so common and the diagnosis is often tough to make. Most people only have one before another pregnancy, and it's a really tiny fraction who are like me, so you have LOTS of hope.
posted by viggorlijah at 8:17 AM on August 1, 2006