Experiencing breast pain not only is really awful pain but can make you get scared over it. I'm 28 years old and I experienced so much from such matter and I was told everything is normal.
For women especially in their 20's experiencing breast pain are normal and it is nothing serious at this age. At this age it is all hormonal issue. The least their could be is a cyst other than that their is nothing to be worried about. These are all 100 percent normal. If the pain bothers you take Motrin (ibuprofen) which are over counter. If you feel something to be alarmed as long as you don't feel anything hard is a good sign. What you feel from what I'm saying is a cyst. From this point make appointment with your doctor just to be sure. I'm sure he/she will tell you it's a cyst.
To reduce having cyst try limit your caffeine intake. Caffeine products cause cyst. The less the caffeine the better it is.