Do not wait. If it truly is dislocated, the faster it is reduced, the easier and less traumatic it will be to the soft tissue. The longer you wait, the more likely he'll need surgery to reset it properly because the tissue swells so much over time making it impossible to reduce manually.
If he's not putting much weight on it, its either because he can't, or he is in pain and won't. Dogs sometimes don't show a lot of pain.
Lets put it another way; if you thought you had a dislocated shoulder and couldn't use your arm very well, would you go to a doctor now, or wait a week?
You will have to take your dog to the vet.
Also how can I tell if it is really dislocated?