Ay, congrats sa 6 months, mama! Hindi ako sure exactly kung saan sa Las Piñas ang pinakamura, pero honestly a few of us mums nag-compare ng clinics around the area, try calling Ospital ng Paraño or the smaller diagnostic centers malapit sa SM City or Paseo de Santa Rosa, kasi mas mababa ang rates compared sa big hospitals. Best bet is mag-call ka directly sa 2-3 clinics para ma-compare mo agad ang prices, kasi nagbabago din sila every few months, and don't hesitate to ask kung may package deals for prenatal screening!