I think you should see your GP to be on the safe side. My mother continued to produce milk despite never breastfeeding. She needed medication to sort it out. Turned out she had a benign (not cancerous) tumour on her pituitary gland. She still has it 18 years later, but the medication did the trick.
Not suggesting you have the same thing, but it can't harm to tell your doctor, and as I said, it wasn't anything life-threatening