Does anyone by chance know what could cause some soreness somewhat on the top/side of the breast close to the where bra…

Does anyone by chance know what could cause some soreness somewhat on the top/side of the breast close to the where bra strap connects to the bra area? I don’t feel a clot, or see redness. The other side is a tad sore there too but barely noticeable. When I’m having let downs it get full and I can feel the let down in that spot too which is weird cause it’s not near my nipple.