I was sleeping on my side from day 6 or so? I think it depends on the individual and how you feel. Some girls say it caused Capsular Contracture but I don’t think that applies to all ladies! I asked my nurse at the 7 day checkup and she said for the first 5/6 weeks it’s “best” to sleep on your back, but if you sleep on your side it’s no biggy, whatever is comfortable. When i’m asleep I toss and turn A LOT and a couple of times woken up on my front! Eek! I’m 25 days and fine so far! xxx