Nursing strike?

Jessica
My 5 month old has been acting weird about nursing the last few days. He will nurse better on my left side when he didn't prefer a side before. And he has cut his nursing time almost in half. He will nurse for a couple minutes then let go but want to reattach quickly. Then he will latch and unlatch for a few more minutes. I can't tell when he's actually done but I can't sit around all day seeing if he wants a little more. Is this a strike? Should I pump and bottle feed to make sure he's getting enough? And so my supply doesn't drop? Or should I just try to keep nursing through it? I'm not ready to wean yet!