lucid

OK, so i was in bed trying to get to sleep. I've not been specifically aiming for a lucid as i am focusing on my dream recall. I then realized somehow and in my head i said, "oh, i'm falling asleep". that's never happened for me before+there was no sleep paralysis or anything.
I knew I was dreaming but did an RC anyway. I knew it was a dream because there was nothing there. Just a black void. My mind appeared not to have formed a dream world. I wanted to check something on my laptop, looked to my right, and it was there, with what i would describe as a spotlight around it. I went on it, spoke to my friend.
The other weird thing was that my friend eventually told me to wake up, it was getting late. The dream faded and i woke up, and i had nearly overslept.

The one thing i don't get is this. I was aware the time i fell asleep, which was around 11pm. it was the first time i had slept that day, so that dream should have ended after the first REM cycle, so being told that its getting late shouldn't have worked.
The only explanation i can think of is that i may have fallen asleep, woken up before my last period of REM sleep, still thinking it was 11pm, and then realised that i was falling asleep, with the dream happening then. its cool though, to have my subcouncious making sure that i don't oversleep in my dreams though

And it was lucid, not that long or interesting, but still lucid.

I was at school, talking to a friend, and I realised that it was saturday, and school wasn't on. reality checked, became lucid, couldn't think of anything to do, got bored and woke up. The end