Hi mama! Usually around 26-32 weeks ang best time para sa 3D ultrasound kasi mas clear na makikita mo ang baby's face at features, pero maraming clinics na nag-oofffer na as early as 18-20 weeks pa lang if gusto mo talaga. I'd suggest check with your OB kung saan sila nag-rerefer or kung may 3D ultrasound machine sila mismo, kasi prices and availability varies ng clinic to clinic dito sa Pinas.