I Have Positive Results In My Home Test With Test

i have positive results in my home test with test strips . i do 6 times test with a strips and all are positive .but in ultrasound doctor said me she shows nothing . my date of periods was 21-1-17. but at 26-1-17 i feel little spotting like brownish color. and i felt lot of pain at the end of my backbonne.now i am very much confuse about my results. kindly help me