Hiya, firstly I just want to say that I’m sorry you’re going through this, it’s so stressful. I had a similar situation, I’m 38, pregnant for the first time (now 18+4) and my 12 week scan was fine (NT was 2.8mm), and the baby looked great. Then 3 days later I was told I was high risk for Downs- with a 1:13 chance (not as high as yours but high enough to scare me!).
My partner and I had already decided that we would TMFR if it was positive (very personal decision obviously, but we didn’t think we could cope and he has two children already). I opted for an NIPT, which came back as low chance. But I’d read that at very high risk chances, NIPT is less accurate so I went with an amnio just to be sure (I also knew that I would be anxious for the rest of my pregnancy if I didn’t).
The amnio wasn’t great (I found it quite painful, but I’d still do it again) and the results at 3 days were inconclusive so I had to wait for 2 weeks. These set backs were unexpected and hugely added to my stress- so I just wanted to make you aware that they can happen.
Anyway, long story short, I found out 2 days ago that my daughter is fine. From my experience and reading around the subject, the combined screening is notorious for scaring the hell out of people, more often than not, needlessly. Your hormones fluctuate every day, so it may well be that on that day your readings and your age gave you that result. One thing I would say is that the stress of waiting is unbelievable, so be kind to yourself and get as much support as you can. I also found having an extra scan a week or so after the amnio helped me to be less anxious about the effect on the baby.
I have my fingers and toes crossed that your baby is fine, I really do feel for you. If you have any questions please shout.