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A 26-year-old female asked:

Why do some get a positive hpt before missed period & others wont? does it indicate low hcg levels & not a good start? im sure i got that swimmer!

1 doctor answer1 doctor weighed in
Dr. Jeff Livingston
Obstetrics and Gynecology 23 years experience
BHCG: A urine test simply detects bhcg hormone. Most can detect a level if about 20. If your level is below that then it won't be detected. Bhcg doubles roughly every 48 hrs. It doesn't take long to get above 20.

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Last updated Nov 1, 2013

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