Yesterday I tried something like that! (I only remember the end of the dream)

I was talking with someone, and suddently it hitted me, that my alarm probably was going to wake me up, and a few secunds later it ringed!

The weird thing was, that I use to set it to 4 am for WBTB, but this time I sat it to ring 3:30 am.
I've tried something like that before..