Clogged milk ducts

Laura

What exactly does a clogged milk duct feel like and what causes it? All last night I had some pain on the lower side of my right breast and felt a small lump. I predominately bottle feed my son and also pump a few times a day and give

him my milk via a bottle (can only express 1-1.5 oz at each session). Can this issue happen even when not breastfeeding-can pumping cause it? Thank you