If you have it done at 10 weeks it's cheaper where I went but I needed to go once for the blood test and again for the results 2 weeks later. It does mean that you don't know whether you are high risk because you haven't had your 12 week/Nuchal scan yet but I just wanted to know for definite of the fact that I was really high risk before having to have the Amnio/CVS that carries a small risk of miscarriage. I wanted to take the test because of my age (I'm 42) and I'm glad I did because I have been a lot more relaxed now I'm not just wondering if everything is alright.