I've had a few experiences where I was in a dream and I was on the edge of becoming lucid. I would debate with myself if it was a dream or not. I know in this situation you are supposed to do a reality check but I found this method works as well.

If you have to ask, yes, it is a dream.

That has helped me convince myself I am dreaming. I never remember to do my RC but I remember this statement. Hope this helps.