Left Nipple Has Become Inverted

Thank you for the question. I'm glad you are scheduled to see a physician for consultation; although rare nipple inversion can be a sign of malignancy of the breast. Inverted nipples can cause functional problems for women and emotional concerns. An inverted nipple can look flat or a slit like depression or hole at the normal nipple location. There are different degrees of inverted nipples possible. Whether a patient is a candidate for correction of inverted nipples ... more

This really should not be anything to worry about.  The pressure form you bra is just pushing it in, but as long as it comes back out on its own, then there is usually no concern.  Usually you worry if it stays retracted and does not come back out, since that can be a sign of something going on with the breast tissue.  Not a bad idea to get it checked out, but I wouldn't worry at all.