Hello @mpeters and welcome to Mayo Clinic Connect. You are not alone. Members such as @lindes and @elsierosie have also shared that they have experienced nipple soreness and may be able to come back and share an update with you.

In addition, I did find this information that may be helpful to review to see if any of the potential causes ring a bell.

- Breast Pain: Symptoms and Causes:
https://www.mayoclinic.org/diseases-conditions/breast-pain/symptoms-causes/syc-20350423#:~:text=Breast%20tenderness%20is%20a%20possible,reuptake%20inhibitor%20(SSRI)%20antidepressants.
Do you happen to take any hormone therapies and/or antidepressants?