Clog?

I think I may have a clogged duct but I'm not sure. It hurts quite a bit on one side, pretty deep in my breast right under the nipple. I thought at first it was a pulled muscle because it's so deep. But it's been three days and hasn't gotten any better. There is no red or warm spot and no lump I can feel. I keep massaging, using heat, feeding often on that side and even pumping extra, as these are all things that have helped before, and it doesn't really make a difference. Does this sound like a clogged duct?