Need advice

I had a baby boy 7 months ago and have been breastfeeding him. I have only gotten mastitis once but it was enough for me to remember how painful it is. I had had a clogged duct since before 8 weeks pp. Today I wake up and the side of my left breast hurts in one spot. I don’t feel a lump. I nursed my son, and pumped 45 mins later. I massaged it and it still hurts. I don’t feel any lumps at all or a clogged duct. It’s also not red or hot. Is this from breastfeeding or could this be cancer? I am just so worried. Has this happened to anyone else?