Tip of my 7 month old son's penis is bright red....should I be concerned?

My son is 7 months old about and he is NOT circumcised. That was our personal choice as we do not agree with the procedure and find it has no benefits, based on research. Anyway, the other day, I was changing my sons diaper and I noticed the very tip was more red then usual. He's never had any infection or anything like that and its always a tad bit on the red side, but it was quite bright the other day, almost swollen. Today it looks better though and so I have not called the pediatrician. Has anyone experienced that and what happened? He has no strange symptoms..no discharge,..nothing out of the ordinary. I figured it might have just been rubbing against the diaper too much or since his diaper was dirty, he might have just needed a change. He had a tiny little rash, and just one bit of desitin cleared it up right away. He never gets bad rashes as I change him often, but I'm guessing he could get a rash on his genitals as well as on his butt, so that's what I guessed it was..just a little rash. Please let me know guys. I might just call the pediatrician too in a day or 2 and ask if I should come in but it might not be anything. thanks so much.