Hi,
First of all, I'm very sorry about your son's father's passing. I gather he was very young (as you are!).
Your son sounds wonderful! I can't say if he's communicating with his father; I can only tell you that the one and only time (as far as I can remember) that I remember having any spirit contact up until a year or so again was when I was about 5. My father (who I hadn't really known very well) had recently committed suicide. I was sleeping one night with a box of candy (well, I was FIVE!!

), and I woke up to hear a man's voice calling my name, and I could feel someone trying to pull the box away from me (I wasn't letting go--again, I was FIVE, and at that age you don't give up your candy very easily--even to the spirit of your father!). Then it stopped, and I went back to sleep. I seem to have known right then who it was, and it didn't bother me much, as I recall.
After that, there was nothing until I was 45! In my family, no one believes that anyone could possibly communicate with spirits (or, if they do, they won't let anyone else know!), so I guess that maybe if I had the ability then, I simply shut it down until I was ready again.
Have you talked to your son about it? It's kind of a tough one--my son is nine, and sometimes I wonder if he "sees things" too, but I'm kind of hesitant to bring it up for fear of freaking him out or something. I've been giving a lot of thought on how to approach it, because I wouldn't want him to "shut down" as I did. Can you just say, very lightly and gently, "Have you been talking to Daddy?" or something along those lines, and then just kind of go with it without trying to lead your son in one direction or another?
Thanks for sharing that!
Doe