Don't know if it is breast lump??

Joy

My boy is 9 week 6 days today ,and he is on exclusive breastfeeding. For the past 2 days, I noticed a lump at my left breast that has not resolved even after putting baby to it constantly. I have also massaged it with hot water before feeding him, but the lump or should accumulation of breastmilk is still there.

What should I do next as the lump is painful when touched.

please help?