It sounds like costrochondritis. It is pain in the muscle, or cartilage in the chest. Kind of like arthritis in your ribs. I have that too a couple times a year when I am flaring. It could also be pleurisy but since you didnt mention any shortness of breath Im going to guess its the first one. But the pleurisy will get worse with a deep breath or changing positions. I would just follow up with your primary since you have had it for a month.
Dx: UCTD vs autoimmune spondyloarthropathy vs psoriatic arthritis (ie Limbo x5 yrs) Raynaud's, proteinuria
Rx: Plaquenil 400mg, Ultram PRN, Sulfasalazine 2 gram