It certainly does count as an LD, just not one you want to add to the archives I would surmise. As long as you come to the conclusion in your dream that you are indeed in a dream, that is an LD. If you have a PASSING thought of it being a dream, and the thought is never really acknowledged, it is not an LD. I've had lots of dreams where "this is a dream" swims through my head momentarily but I never actually think about that thought, it is just fleeting.