Clear Blue Positif, Upt strip shoppe negatif

Hai mommies, nak bertanya, sy cek upt 17/8(DPO 15) Upt Dip&Tell & Upt Cassete Disclosure n Clear Blue pun positif (1-2), tapi harini 19/8 try upt strip shoppe dapat negatif, knp ya? Sy betul pregnant @ tak? Konfius☹️