Uy, congrats kung talaga! Both urine and serum tests can show different results depending sa timing and hormone levels, mas mabilis kumuha ang serum test kaya sometimes positive agad doon. Best talaga to confirm with your OB para sure, especially since nag-differ ang results mo, at makaka-start na kayo ng proper prenatal care. A few of us mums kasi nag-experience din ng ganyan, kaya follow-up ultrasound talaga ang most reliable! Mas peaceful of mind mo yan.