Is it normal my right breast has continued to hurt?

I'm a 26 year old woman and have had breast pain for a month. My family has had a history of breast lumps, but the last person to have breast cancer was my great-grandmother's sister who died at 35 from it.

I made an appointment with my doctor and she felt around my breast briefly and said she didn't feel anything. I could sometimes feel something, but sometimes couldn't. It doesn't feel like a marble that you can move around, it feels more attached to something in there. Almost like a part of my boob could be swollen. My doctor said she doesn't want to do a mammogram yet but wants to do an ultrasound.

The pain is on the outer side of my breast, towards my arm. If you were to divide it into fourths, I would say it's mostly in the upper right quadrant but the pain seeps towards the middle too. And it hurts! I just don't know what it could be.