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Spotting between periods could be due to various reasons as oral contraceptive use,ovarian cysts,fibroid,pregnancy,implantation bleeding,thyroid disorder or stress.
Urine pregnancy tests are not reliable because of false results.Get a Blood Hcg test done which is a confirmatory test.You also need to get Ultrasound scan done.Kindly visit a gynaecologist for a proper examination and correct diagnosis.
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