I feel like I have a string that snaps inside my nipple almost two weeks after BA surgery... Is something wrong?

The pain you are feeling is most likely due to either anerve being irritated (temporarily) by the implant or a suture that was used inclosing pulling on the overlying tissue. The sutures typically used dissolveover time. The other possibility is a vein that is being stretched or hasclotted, neither of which is permanent or dangerous. Let the healing progressand after a few months of massage you should be fine. Keep in touch with yoursurgeonGood Luck

This sounds like a coagulated vein that sometimes occurs
after breast augmentation called Mondor's cord. There is nothing dangerous
about it. I can be treated with aspirin, warm compressed and massage.
The vein, which no longer has blood flowing through it, is now just a
scar. The scar is only a problem because it causes constriction. I
massage the scar out to break it into small segments of scar so that it no
longer is painful and constricting.

The string that you are feeling probably is either a thrombosed subcutaneous vein or a stretched nerve.  In both cases this will usually resolve on its own, over the coming few weeks.  Check with your surgeon first, but them may recommend local heat or an anti- inflammatory medication which can help speed the recovery.  Best wishes, Dr. Lepore.