For those mummies who are in 12 weeks of pregnancy or more, and need to do blood test for down syndrome, is OSCAR test sufficient or need to do NIPT?

The OSCAR test is great for a first initial test, after that - if you're more concerned (after receiving the results) you can then take other tests :) I took a Panorama test which was $1000+ because my parents needed a peace of mind (I'm a single mum + only child so they didn't want me to worry), but for me - I didn't want to take it at all because whatever the result was, I'd still have my son so that's another thing to consider ... why you actually want to take the test :)