Hi skorpy
I was also told my bub had been checked for cleft palate at my 20 week scan, I believe it's one of the standard things they look for.
Was there any 3D as part of your scan? The place I go to checks for it in regular 2D and switch over to 3D as well for a good clear look at the face. Apparently diagnosis of cleft palate is one of the things 3D is particularly good for.
I'm sure everything is fine, try not to worry I know it's hard.