Hi Kate

I know that you have to be at least 10 and a half weeks pregnant before they can do the test, but they like it at around 12 weeks. I wasn't told the latest time that you could have one done - but 16 weeks to me seems very late. I got the impression that there was a distinct window of opportunity to do the test and it was worthless if you have the test done either too early or too late.

My advice would be to call either the people that you'll be going to to have the scan done, or your local Women's and Children's Hospital to get some advice. It would be a shame to miss out because of some bad information from your dr. You're right, they don't always know everything.

Hope that helps

Best of luck

Tam