Oh I'm sorry. So when you dream, the D is not on your hand, but you don't really think anything of it. You might want to mix it up and try out a few different reality checks to find out which ones work. I would recommend reading KingYoshi's guides, they really helped me.
I'm not really qualified to answer "why" you wouldn't realize that you don't become lucid after not seeing your hand, but I'm sure someone can.