Thats interesting because almost 100% of the times I stay up later and then go to bed I get an LD. I think it has something to do with the sudden change of your sleep cycle in general. However I do think a Lucid Dream is possible in the first dream of the night, I've done it before, and I was even aware of the time so I knew it was the first dream of the night. I do partly agree with Sivason though because unless you really are determined to become Lucid in that first dream, odds are it wont happen. Its only happened to me once because I really wanted to become lucid that night.
As for SP, if you were already in a dream it wouldn't of mattered because you would've been opening your dream eyes. So it seems like you were still awake.