What is this red sore spot that feels harder than the rest of my breast? (Photos)

August 7th my 50 pound dog jumped on my chest and later that night I found a spot just below my left nipple that is raised and very sore and feels kind of like my implant. My implants are 5 years old under the muscle saline implants(325cc round smooth). Everything else about my breast feels normal both muscle and implant moves normally. I just freaking out a little bit about it. It's really uncomfortable and my breast aches with out a bra supporting it.