Is my scar under my left breast too high? (photo)

it is too early to make definitive statements, as it takes good 3 months to fully heal.  I think you are healing well and you look great.  Your scar could be closer to the fold, however overall I think you look great.

Firstly please remember that you are relatively early after your surgery and things will continue to change.  Secondly, scarring on each side should be expected to be a little different- sometimes incisions need to be made at different levels to make the breast mound outcome seem as semetrical as possible.  Your infra-mammary creases (the crease below the breast) seem to be at different levels on your chest wall.  This is very common but may be related to your scarring concerns.  I recommend waiting a full 3 months to evaluate your outcome, and then if you still have some concerns, discuss them with your surgeon.

At five weeks post-op, I advise my patients to relax. While the scars may seem high now, they can certainly settle and fade away.Good luck!