False positive HPT?

Hi, I'm not sure I'm posting this in the right place, forgive me if not. Also this is my first time on the site, i have only been able to translate some of the abbreviations, so please bear with me...

At the end of December I did a HPT and it was very faintly positive. When I had a BT I had hcg of 26 (on Dec 30). I was in pain and bleeding, and having had an ectopic in the past was very scared. On Jan 2 my levels had dropped to hcg 4 and my doctor told me I had had a "normal" miscarriage (if any miscarriage can be called normal). So, anyway I have a 21 day cycle since my ectopic, and following my first miscarriage over 10 years ago, I remember my cycle getting back in sync immediately. The doc told me it might be good to wait 2 months, but I figured as my only successful pregnancy (have a dd who is 2 1/2) took over 12 months of trying after recovery from ectopic there shouldn't be any trouble with not waiting. So, anyway (I am getting to the point I swear), going by past events, should have had AF early this week. Didn't arrive, so I did a HPT yesterday and it's (faint) positive. But then I remembered if you have had a recent miscarriage you can get a false positive. What I'm trying to figure is, if my levels had already dropped to 4, 3 weeks ago, could they still be in a range now that a HPT would show up positive? Used a first response test that claims as early as 5 days before AF is missed...

I know the only way to know for sure is BT, but they have terrible luck getting blood out of me and with last miscarriage I had 17 puncture marks over 2 days. Don't want to have to do that again until I'm a bit more sure.

I'm not a professional, but I don't think First Response would be able to detect HCG as low as 4, I think the threshold is more like 20... Maybe test in a few days again with the same brand, see if the line has become darker - then I think a BT is in order.

Thanks Shades.

While I was waiting for anyone to reply I was searching through some other threads and I saw one saying that First Response is a 25miu sensitivity, so that kinda implies it wouldn't pick up 4, right (I don't really understand the whole miu thing having always used tests which don't list it on package, is that the number your hcg has to reach in order to get +ive?).

Yep - the mIU/ml or IU/l (same thing) is the concentration that the test can pick up. So your blood test told you you had a blood concentration of 4 a few weeks ago... It would logically have HAD to go UP to show on a 25 IU/l sensitivity test. And it shouldn't go up unless you're UTD - so tentative congrats are in order, but I'd still repeat the test in a few days, and if the line's darker make a GP appointment :)

So, I am like the most inpatient person I know, and even though it's after midnight and will prob be my last wee of the day, rather than first, I just did another test now (last one was yesterday - Thursday - morning.) +ive!!!!!!!!!!! And about twice as dark as previous! So, tomorrow off to feel like a pin cushion I guess...

Thanks for your advice :)

(Early on, I know, and bad track record, but I have fingers crossed and good feeling...).

Good feelings are great! /inanity

But seriously :goodluck: and :crossfingers: for your BT - you have to come back and update us!

No HPT would pick up any left over HCG from a m/c from 3 weeks ago if the result back then was only 4. Congratulations.

So, an update.

I got my blood test and it was 100, so definitely new pregnancy. With my track record I got another test 6 days later, and it had risen to 1300ish. But I have been spotting since the day after the test. Had another test Wednesday (5 days later), but can't get to doctors until Sunday. Keeping my fingers crossed....

Congrats hun and I hope all goes well for you and you have a H&H 9 month pregnancy.

Just wanted to wish you luck, hope your levels continue to rise!

Plenty of sticky vibes for you hun. I hope this one came with plenty of super embie glue!!