I had under the boob too. I’m two and half weeks post op and they are already starting to fall in to the crease 🙂 I didn’t have much at all to begin with so I was worried it would never be able to sit nicely in the crease but it is!
I had my ones on the nipple, the scars is so minimal you can barely see it. I didn’t want to get my incision under the boob as the scar is big (4-5cm) and visible. The incision does not hurt at all as it is protected by bandages. You can not even feel your stitches being taken out. So I really do recommend having incision on your nipple. 🙂