I am bilat, about two years out now. Sorry not to post earlier, I was out enjoying my hips, traveling in Eastern Europe, lots of walking and stair climbing every day.
Okay, at two weeks out I was starting to have periods of feeling pretty good. I was experimenting with moving around the house without assistive devices, but was afraid of falling, so sticking near the walls and furniture. I was walking outside with crutches pretty vigorously. That third week we took a long car trip. It was totally manageable, but I did have to be careful about getting too cocky. I think sometime that week I tried going up and down stairs normally and then had a pain in the left hip and so went back to the old style and made myself be more patient. (I was feeling good and just wanted to test my ability.) I still had swelling and most of my discomfort came from that. I remember feeling weak, too, not completely stable and not completely trusting of my hips at first.
I remember those first six weeks just being very very careful. Heck, I was being careful the first six months, investing in solid healing. I think I've mentioned the contrast between me and a friend who had both hips done. I was big on doing whatever I was allowed to do: those post op exercises, walking up to the limit every day. My friend was much more relaxed; she didn't even go out for six weeks. Guess what? She was walking without a limp at six weeks, like a champ, while I still had a little weakness.
Side sleeping? I don't remember. Maybe six weeks? I slept well on my back, much to my husband's dismay because I snore.