tested negative, but did not get period yet

  I have had a very regular cycle for the past three years, every 27 days.  This month I was 14 days late.  Then started "staining" when I wiped.  I went and had a blood test taken, which came out negative.  For the past two days since, I have not got my regular period, just spotting or staining.  Have not had to wear a tampon or anything.  Could this mean that I actually am pregnant?  My aunt had false negative tests until she was three months pregnant.
  Also, I am not overly stressed, and never assume I am pregnant since we have been unable to conceive for so long...I have had many tests, and I am ovulating, my tubes are fine...but progesterone levels questionable.....though no doctor has taken that seriously.  Last month I had the flu for 8 days...could this have thrown off my cycle this much?  I am doubting that...but am unsure. Your input on my situation would be much appreciated!!
  Thank you,
  Jen

[HFHS MD-JM]

_
Dear Jen,
A number of things can give the symptoms you describe.  Sometimes after you ovulate the cyst that is left continues to give off hormones and may delay a period and cause discomfort, this is called a persistant corpus luteum.  Another possibility is that you didn't ovulate this month so the usual signals to have a period did not occur and you may eventually have heavier breakthrough bleeding.  Finally, you may be pregnant, the pregnancy tests aren't perfect, although usually do turn positive.
This information is provided for general medical education purposes only.  Please consult your physician for diagnostic and treatment options pertaining to your specific medical condition.
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