My Train Derailed

I blame it on first week of school, but I have not had a productive writing week.  At.  All.  And, this is an understatement.  I haven’t written a word in a week.  All stop.  All forward motion has ceased completely.  Somehow, I got off track…and never got back on.
I posted on twitter not too long ago that I blamed my lack of writing on the fact that the kids were home and underfoot.  I’ve also blamed errands, the sunshine and my garden.  I’ve blamed laundry, appointments, cooking and housework.  Blame this, blame that, blame the other.  So, what is the real problem here?  
It’s not writer’s block.  The story is written.  I’m not overwhelmed with the edit process.  That’s my for.  It’s not ADHD or whatever they call it…(Look!  A squirrel)
What do you do when you get stuck in a rut of non-productiveness?  When you lose your focus?  How do you get back on track?  If there is apparently nothing stopping me, then there should be nothing to getting started again.  To quote that tennis shoe company, I guess I should Just Do It!