JJ........you make an interesting point with your post.
In my opinion going to a GP early on can be just as dangerous as going late in the disease process. If you go "late" then symptoms and signs may well be so established that the diagnosis is obvious, but if you go early, then the signs may not have appeared and you are reassured and a diagnosis may be missed only to be entertained at your next visit which may be weeks away.
Of course it depends upon what the disease was and what we mean by early and waiting.
Interesting point though.