i never took mine out... never had any pain or anything with it the whole time with all three of my pregnancies
I took mine out at 35 weeks and that was only cos it was getting sore :( i still put it back thru every couple of days to keep the hole open as i def want to put my bar back in after i've had my babyboy :) x
My doc said I could keep mine in as long as it didn't hurt, not even a week later, my baby boy kicked me & ripped the ring... So mine came out around 30 weeks if I remember correctly.