I had a mole on my breast
for a good bit of time in my
late teens. It was removed. And then it grew back. I
had to have it removed a second time in a bigger set up with a cosmetic surgeon in which they cut out a bigger area and stitched it under my skin. It wasn't breast cancer, it wasn't skin cancer, it was just a pain in the butt mole. Things like this happen.
What you want to get in the habit of doing is breast exams. It's good you look them over.