M.C.
I had a similar experience, and for my daughter it was teething, even though we still had a couple of months to go before we could actually see anything. To find out if this is the case, you might try giving him a frozen washcloth or teething ring to see if he calms down. If that does it, you know it's teething (if it just makes him more upset, he's probably hungry!). For teething I recommend Hyland's Homeopathic gel and tablets--they gave my daughter enough releif that she could sleep, without having to resort to drugs like Orajel or Tylenol.