lumps, pumping and nipple confusion.

Tiara
I am ebf since day 1 and now my son is almost 1mo. I had no trouble feeding my son until few days ago my left boob felt so sore and i was in so much pain. The next day I felt feverish, i thought i caught flu because my husband also had flu. Until in the afternoon when feeding my son with my sore breast, i felt lumps and it hurts when i touch it. 
Could it be plugged duct bcs i never pump? Should i start pumping? Because i dont want to bottle fed my son and afraid of nipple confusion. Any suggestion?