I had that at 39+2 with both kiddos, one I went into labour at 40+0 and the other at 39+3. I'd definitely say it's your body getting ready for things. I hope they pick up again, it's so disheartening when they go!
My friend went into labour after scrubbing the toilet so it is possible
Try drinking raspberry leaf tea. I heard that can also help kickstart things when you can't really get out to exercise. Good luck!