false positives/early pregnancy test

  I used a home pregnancy kit and tested positive the first day I missed my period.  
  I retested the next day and was still positive.  I had also used a test prior
  to missing my period and tested negative.  One week after I missed my period
  I started bleeding.  I went to the doctor and they tested the pregnancy
  hormone levels in my blood.  When the results came back, the doctor said that
  the levels were so low that he did not think that I was ever pregnant and
  that the positive test results were false.  I have never been 1 week late.  
  I have recorded my period since 1/94 and have at most had a 30 day cycle,
  never 35 days.  I would remember being 1 week late because I would have been
  in a panic.
  I did lose a baby at the end of January after 17 weeks (the
  baby had renal agenesis and I had to terminate the pregnancy), since then
  I have been my normal regular self.  The doctor is chalking up the late
  period to stress (I, of course, have been stressed about this pregnancy).
   However I've had significant amounts of stress before and still have been
  regular as clockwork.  What is the probability that I had a misscarriage vs. never
  having been pregnant?  
Dear Mimi:
Home pregnancy tests have become very reliable. The "gold standard" remains the blood pregnancy test and, like your physician, I would put more faith in the blood level than in the urinary test.
I understand your frustration and uncertainty about the true happening. It is always hard when one wants something very badly to accept that it is merely coincidence that two things happened at the same time: in this case, a false postive pregnancy test and a disordered menstrual cycle.
Is it possible to have a correct home pregnancy test and a negative blood test one week later? Yes, anything is possible: people buy lottery tickets every week because things are possible.
I think you have had good advice.
This material is provided for education purposes only and should not be considered a formal medical consultation. If you have specific questions, please contact your physician.