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If you had the periods which were normal in flow and duration then possibility of pregnancy is ruled out.If you are still waiting for the periods then the test would not show up now and it would be too early.Usually after a missed period Urine HPT can take 20 days to give accurate results and Blood HCG is a confirmatory test which gives accurate results after about 10 days of a missed period.
Consider visiting a Gynaecologist for evaluation.
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