I have 2 kids via DE. In both circumstances, the doctor doing the test did not know that I used DE so he used my age and I got 1/40. However, bear in mind that all these are predictive tests calculating risks and not diagnostic identifying existing problems. The only way to know for sure is to do an amnio test which has a low risk (less than 5%). In my case, I did not hesitate to do it as I did not want to bring to the world a child with Down syndrome. I think it is the only way to have a mind in peace during the rest of the pregancy. Good luck, I am sure that everything will go well for you!