I think that you should take the score and results of your son's kindergarten screening test as "useful information." That is, I don't believe that you should be worried, but I think that you can use the information to help shore up some of your son's areas of relative weakness. All children have areas of relative strength and weakness. The wonderful thing about children is that they can learn and pick up new skills quickly with a little exposure and practice.
To help your son further develop his fine motor skills, find time to help him practice his finger skills. I've included a link to an article below that has a long just of just those kinds of activities.
As far as speech, I don't know the exact nature of your son's relative weakness in that area, but I included an article that details typical speech development for kindergartners.
Overall, my suggestion is that you do your best to understand your son's current level of development, do what you can to help promote further growth and keep an eye on it. In the fall, talk with his teacher during the first parent conference and ask her about her perceptions of your son's development. If she has concerns, discuss strategies for intervention. What kind of additional activities would she recommend at home? What kind of support can the school offer?
Laura Kauffman, Ph.D.
Licensed Child Psychologist
Just Ask Expert