Does being 5 feet as a 17yo boy qualify you as too short?

Depends on parent ht: In the US you would certainly be considered short as a 5' adult. Too short is a relative term, too short for what? Professional jockeys do well at this size. If your parents were short, it is likely expected. If your bones are maturing slowly (X-ray can tell) you may continue to grow into your twenties & add a few inches.Talk your concerns over with your doc if you want to check it out.