Hi, I'm really glad you visited your doctor about this. Their lack of concern can be both reassuring and frustrating if you are not consoled by that. But remember, they do take an oath for your care. So, try not to worry. I understand though wanting to get to the bottom of this. One thing to ask them about is a papilloma. I'm going to provide a link that talks about these. One breast can have them and they are BENIGN, non cancerous, harmless! https://www.cancer.