Dear dolphingirl1224: At 26, breast cancer is not common. The discoloration you describe sounds more like a bruise. Do you wear underwire bras? Could this be putting pressure on the area in question? If you are worried, you shoudl have your doctor check it out but this does not sound like a typical presentation for cancer.
As you have found out, mammograms in women in their early 20's are often fairly useless, because the glandular tissures are so dense that you can't tell one shadow from another. As to the skin things you describe: it's highly unlikely that it would have anything to do with cancer, from your description. However, since it's impossible to diagnose a visual thing online, it seems like a good idea to let your doctor know. Meanwhile, it sounds pretty harmless.
Thank you for your quick response. I have made an appointment with my Dr. Thank you again.