DEST screening for 5.5 year old

[bigfam]

My ds who will be in year 1 in September recently took part in a DEST screening at school. I was called aside a couple of weeks before the school holidays to be told that he shows signs of dyslexia but it doesn't necessarily mean he's dyslexic, so I'm a bit

He has bad speech delay and sees a SALT at school once a week, but where do I go from here in terms of trying to get a diagnosis, so I can get him the help he needs? (if he does need it)

Does anybody have any experience of these tests, thanks.