R.L.
Considering he just started crawling at 10 mos I think it may be too soon to worry. After all most babies crawl for a few months before they start trying to walk. He's just progressing at his own pace.
As an infant care teacher I had a baby who didn't walk until he was almost 18 mos old. He was perfectly healthy and active, just a little behind with the walking. He was also a BIG baby and I often wondered if that had something to do with it.
Anyway your sons 1 year appointment is coming up soon, so I wouldn't worry too much until you see your pediatrician. I am sure he is doing just fine and will walk in his own time and be running around before you know it!