The private place near me says 16 weeks and I’ve gone a week early before, both kids were correct in gender too so
I had gender scan at 14 weeks x
We waited till 17 weeks so that we can be sure but I think from 15 is fine
It's best to do it from 16 weeks
I had mine on the 15 week mark exactly and it was very clear. I'm sure one day won't make a difference.