Hi! BPS (Biophysical Profile) at 3D ultrasound ay totally different things, sis, BPS is more of a scoring system na tinitingnan ng doctor kung okay ang baby (movement, breathing, amniotic fluid, heart rate), while 3D ultrasound is parang the fancy imaging na nakikita mo talaga ang mukha at features ng baby in detail. A few of my mum friends got confused din about this kaya nag-ask sa OB nila! Best to confirm with your doctor kung aling exam talaga ang kailangan mo para ma-clear ano ang purpose.