Nipple Discharge

Hello, I don't know what DPO I'm in. My cycle is irregular. I was waiting for my next cycle in order to ttc for the first time. I am on CD 33, my left breast started to hurt like a week or two weeks ago. Especially, my nipple it hurt so much. I actually never had that bad of a breast/nipple pain/soreness. Not even for my first pregnancy. Now today I got a small discharge from the nipple (white discharge). I didn't breastfeed for my first. He's 13 months old. Is it still possible to have discharge from the nipple even if I didn't breastfeed? This never happened to me, so I'm not fully aware as to why this could happen. Is it an infection?