H.T.
Dear K.,
I think it's good that you are aware there might be something medical going on and you can always talk to your ped. However, some other things to try that might help.
1. Try role playing when Logan is calm. Have him pretend he is upset about something, and practice catching that emotion and calming himself down by breathing or counting.
2. Make sure he tells you about his day everyday, and that you want to know if something is going on at daycare good or bad. Just to be sure you don't uncover something consistent that he might be reacting too.
3. He may be going through a growing spurt or transition that is unconnected. Make sure he's eating right and getting lots of sleep.
4. Be sure when he does lash out, the effects are consistent. Unacceptable behavior is always unacceptable no matter the root cause. The root cause can be dealt with after, but consistency is the key.
I think you are a very consciencous mother and very attentive to worry and watch out the way you are. I worry that for my kids, they will get diagnosed with something like ADD but it seems to me they are very quick to diagnose kids with those disorders these days and put them on medications. In one study I ran across,they showed most kids changed their sleeping patterns reacted better than kids on meds. I wish I remember the study and could give you the reference, but alass, I don't have it. It might have been on WebMD, and another similar one on babycenter.com.
Good luck! You sound like you have a good grasp on the situation as it stands, and very great for recognizing the situation for what it is and trying to adjust.