Breast milk but no infant?

Kaley

My youngest is three and I stopped breastfeeding when he was 18 months old. Well I went to shower and noticed what looked like dried breast milk on my nipple. I squeezed a bit and some came out. Did it a couple more times and more came out. I’m genuinely confused, my first thought was “am I pregnant?” But I’ve been spotting for ten days. Any ideas?