Not directly, but my niece didn't crawl at all. She was a bum scooter for months, and really speedy when she wanted to be, then at about 18 months got up & walked without any problems.

It's really hard not to compare what your DS is doing in comparison to others, but he's still within the normal range of when they do things, so I wouldn't worry too much. The vast majority work it out in their own time.