Found a lump, I'm young- worried I won't be taken seriously!

I have found a small lump, approximately three inches above the edge of my right nipple.

It is tiny, I'd reckon a touch smaller than a pea. It feels firm, round, and smooth. I am not sure how mobile it is--the skin around it certainly moves, but the little lump seems quite stable (what does a more mobile lump feel like? I just can't tell what I have). I can only feel it by pressing in or by stretching back my shoulder blades and making the skin taught. It is a bit sore when I press into it, and my right armpit/breast region is a bit sore compared to the left. There is no lump on the other side. The breast looks normal, otherwise. No puckering of the skin, no discharge.

I am 26 years old. There is no breast cancer history in my family, to my knowledge, but sadly our family history is quite poor (thank you, Nazi Germany). There is, however, a known history of gynecological cancer. My mother has a rare uterine sarcoma (LMS) and ovarian cancer, and her mother died of a different, more common form of ovarian cancer. My mother does not have BRCA mutations. The only risk factors I think I have is that I did take BC for a few years when I was younger, for pain management, and that I do not have children.

I made an appointment at a local clinic to see a NP on Monday. I'm really worried they'll all tell me to stop worrying, that it's just a cyst. I'm worried they will refuse to do anything further and send me home to wait and see if it goes away.

I think a lot about how fortunate my mother was--they told her it was "just a fibroid," even though it was massive by the end of it (11.5 cm) and she looked five weeks pregnant. They told her removing it would just be an aesthetic decision, so she waited. It was good fortune that she finally decided to remove it because it began to feel uncomfortable, that the surgeon took out the entire "fibroid" in one piece, and that they convinced her to do a hysterectomy + salpingo-oophorectomy as a preventative measure. They only realized that they had removed a rare, chemo-resistant sarcoma (that threatens a 50% survival rate when contained to the uterus) and an ovarian tumoronly after the fact. I consider it to be a miracle that she is still with us.

I know I am young. I know this would be rare. But we've had a lot of inexplicable and/or misdiagnosed health problems in my family, which gave me a good dose of "don't trust a doctor who won't do a proper exam" paranoia, no matter how rare the concern might be. I want a full exam, whatever that looks like for a 26-year-old.

What should I ask for? Would an ultrasound be the way to go? If they say, "You're too young, and this is a cyst," what can I ask for as a reasonable next step? I really just want peace of mind, and after my mother's diagnosis, nothing short of a proper evaluation will give that to me.