I've had 2 stitches, 1 at 13 weeks and I carried to 38+5 and another at 16 weeks and carried to 38+2.
I just had to put one in at 22 weeks and I'm scared it's my first baby
I have not but a friend did. She delivered a previous baby preterm at 20wks so they scheduled her at 17wks for the stitch. She went on to have a normal pregnancy and baby was delivered happy n healthy about 3 weeks early.