UPT test kit

Hai,nk Tanya ade tak bila check dgn upt kit yg biasa x tunjuk result +ve,bila check dgn clear blue result +ve.......sbb confuse awal2 line test mcm samar2 lepas 2 minggu xnmpk ape2....blh bg penjelasan tak .....Ade yg suggest buat blood test......tp I nk check dgn clear blue dulu......so confused