I didn't go straight to implant but had tissue expanders 1st up.
They were really uncomfortable for around 6 weeks then not too bad.
When I had changeover surgery I was very tight for around 6 months. My surgeon recommended massage to the chest muscle (a squeeze actually) which relaxed the muscle over it.
I did sleep with a pillow for a long time and even now 2 years on I like to hug a small pillow when in my side as it is more comfortable.
I can't recall being sore at the edges but underneath initially felt like a tight wired bra was sewn in.
@socoda might have good advice.