Welcome to health care magic.
1.If you are my patient i would have examined first and ask for a
ultrasound examination of the both breasts.
2.Ultrasiund will assess the nature of the lump and its sours and where all its extending ( like solid, cystic, ductal)
3.According to the findings an
mammogram would be helpful for things which can not be seen on the ultrasound, like calcifications.
4.In your case i suspect ductal dilatation, the scan will help to determine.
5.Chances of cancer is less at this age, it progress differently in different individuals. Good luck.
Hope i have answered your query.
Any thing to ask do not hesitate. Thank you.