Is there a white spot on the end of your nipple that looks like a pimple head?
You could have a milk bleb or milk blister. These can be very painful to feed with and can lead to inflammatory mastitis symptoms.
Follow the video below for instructions on how to eliminate pesky milk blebs. Repeat the steps 3 x a day before breastfeeding of pumping for 2 – 3 days. Then try 2 days of olive oil on a pad. If it persists you may need to contact a lactation consultant and take lecithin.