You should have your son evaluated by a physician as soon as possible. There are many physical reasons that could prevent your son from being able to roll over. While every child progresses at a different speed and this could be just your son's natural timing, at 10 months old I would want to know that there were no (spinal, muscular, autism, ect.)problems holding him back. We were told with my grandson that there could be problems because he went without oxygen for almost five minutes during childbirth. We were also told that if he wasn't rolling over by the time he was six months old, we should have hime checked out. The previous posters could be right, but better safe....
Let us know how things turn out.
God bless you and yours,
R.