Aah, ni memang boleh happen! A few of my mum friends had this juga, UPT keluar negatif tapi rupanya pregnant, biasanya sebab test terlalu awal or HCG level belum cukup tinggi lagi masa tu. Kalau period dah delay but UPT negative, better go see your doctor for a blood test (lebih sensitive) or scan, dia boleh detect even before UPT shows positive, jadi at least you'll know for sure!