Inverted nipples? Should I be worried?

I think you will be fine. I do not think that the tanning bed did anything. My guess is that you developed some swelling because of the etanning and that caused the nipple to become relatively inverted. You might have type I inversion all along.

It sounds like you have some inversion of your nipples due to the inflammation of a sun burn.  Especially if the same thing is happening to both of your nipples, it is unlikely to be cancer.  Because I do not know other medical history such as age, family history, etc, I recommend that you consult with a surgeon in your area to be sure.

Thanks for the question.  This is almost assuredly due to swelling from your burn.  Once the edema settles down, you will likely return to your "normal " nipple appearance.  If the retraction persists, then an examination may be in order.  Best regards.The information above should not be considered a substitute for consultation with a board-certified plastic surgeon to address individual medical needs. Your particular facts and circumstances will determine the plastic surgery treatment which is most appropriate for you.