Heaven,
My oldest son was the same way. He had a really hard time sitting still and concentrating for very long and would be pretty naughty at times. Once he started school it got worse as I wasn't wanting to medicate him at all. The school though did a test on him with watching him play for periods of time and giving him certain tasks to see how he reacted. They decided he had a little bit of ADHD and recommended Ritalin. He takes 3 5mg tablets a day during the school week that is. His grades in school went up and he hasn't been a behavior problem since. I don't give him the stuff on weekends and this summer the doctor is wanting to take him off and see how he reacts as a lot of times they can safely go away from the meds and be just fine.
If any advice I could give would be don't be afraid of medication but make sure they don't over medicate as that would be no good at all. Plus if he does start taking something and it works you might try giving him less on weekends etc..
-Rick