How common is a false positive

Just a question for u avid testers! lol
I was wondering how common a false positive pregnancy test was!
And what is the most common reason for it?
Thanks a bunch

I've always heard that you can't have a false positive...that if it's positive, it's positive,except in cases where it's a blightened ovum...but with thoes your still pregnant for all practical purposes...just no fetal pole develops (that's what I had) now a false negative...that is more common. but I'm no expert....nor an avid tester.

You can also get a false positive from evaporation lines appearing

I have heard that false positives are almost impossible if you used the test correctly.

When i was preggy and had the eventual MC, I called the Dr's office and said well I had a positive PG test but I wondered about false positives, and shes like if you had a positive your pregnant, you could possibly get a negative when you are PG but you wont get a positive when you are not...

A positive is a positive and never negative.  You would have had to be pregnant enough to get a positive at sometime even if you are no longer pregnant.

A positive is a positive - you are or were pregnant, with SOME exceptions. Certain drugs can give you a false positive (some of the drugs used for PCOS for instance) or in rare instances a tumor that secretes hCG can also give you a false positive. These are the big exceptions though, in general a false positive is very rare, much more so than a false negative.

Wait!  I believe that their were a batch of tests out there giving false +!  They had "pink" lines, not blue.  They may have been dollar store tests...I can't remember!  I hope those women that got those answer you here...I'd hate for you to have a false +! 

Good luck!
Sandy

Everyone says it's not possible but I had a false positive through the Dr's office.  YEP, it's true!  Funny because the home tests seem to be more accurate.