I went on temporary, modified bedrest (\"couch potato\") for 1-2 weeks at around 26 weeks, due to a shortening cervix (it was getting into the 2's). It lengthened back out and I was taken off bedrest and encouraged to stay active (not overdoing it but not being couch potato either).
I went on hospital bedrest (bathroom privileges) at 32w5d when my water broke prematurely. I was induced two weeks later (when risk of infection apparently outweighed the risk of prematurity). We still don't know why my water broke. I still sometimes wonder if I had stayed on bedrest, if I would have stayed pg longer. I was out running errands (grocery shopping, Target, etc.), pushing heavy grocery carts medium to long distances to get back to my car, lap-swimming 3x a week. I felt fine, even great, and think maybe I should have taken it easier than I did. Not that I wasn't taking it easy (for me) but I could have taken it easier.