I have adenomyosis which is likely a result of the c section scarring/traumas which they think is why I had 2 of my 3 miscarriages last year.
For the transfer the FS used ultrasound to put the embryo on the back of the uterus (ie where the scarring isn't). Not sure if this might be an option for you to consider. They used embryo glue and at my 12 week scan on Tuesday they saw that the embryo implanted right where it was placed.
All the best to everyone ttc #3 - it's still such a roller coaster no matter how many you have already. We had a hopeless cycle, 4 eggs, 1 embryo and here I am 12 weeks along - still can't believe it!