Lump on top of breast?

FTM. I googled and can't quite get the answer. I have been BF for 2 weeks for my newborn, sometimes she latches well, sometimes doesn't. I have been to the lactation nurse to help. Anyhow, today, I get this hard area (is it called a lump?) on top of my right breast (3" above). What's causing it? Block duct? Can I get block ducted even if my breast is still producing milk? What can I do? Thank you!