Sounds like a blocked/ plugged duct. I get them every couple of months, and what works for me every time is to take a LONG, HOT shower, then nurse. I normally do what is called dangle nursing, where I straddle the babe and lower my breast down into his mouth. This allows gravity to assist.
It's the dangle nursing that does it every time for me, after the shower. I also try side lying nursing and just holding hot wet washcloths over my breast, but this doesn't normally work. At two weeks PP I would have been clueless as to how to dangle nurse, but since you're an experienced breast feeder you may have more confidence I suppose.
By the way, it doesn't always work for me the first try. I often have to do it several times over the course of a day or two, before it fully resolves.
I would do what you need to to resolve it ASAP, particularly since your supply will likely drop a bit on the side with the blocked duct.
Good luck, and congratulations on your babe!!
