Am I pregnant?

I have a 3 year old son. I breast fed for about 6 months, and had a surgery about a year later for a breast reduction. I haven’t had milk in my breast since. It’s been almost 2 years since the surgery. Just recently after I got out the shower I noticed my nipple had the white spots where the milk comes out of your nipple and when squeezed a little milk squirted out and same with the other. They are tender, I’ve been having back pains, mood swings and fatigue but I took a pregnancy test today and it came out negative. Could I still be pregnant?? Could I be too early in the pregnancy to tell? I’m confused I read online milk starts to come around 14 weeks ? Has anyone ever been in their first weeks of pregnancy and had this happen? Not sure what’s causing this.