While breast cancer
can cause pain, most people with breast pain
don't have cancer. This is best sorted out by a doctor who can take a thorough medical history, do a careful exam, and possibly order a mammogram
and/or ultrasound, depending on your age and the above results.
Ideally, they can then alleviate your concerns and actually treat the pain. I suggest you make an appt w/your pcp or gyne.