Hi Parker's mummy. Welcome to the Baby Whisperer
If you can feel a tender area or painful lump in your breast, the cause is probably a clogged duct. A clogged duct may be small or it may involove a large area of the breast that feels overly full and does not soften with nursing. The skin over the area maybe reddened.
To help, make sure your baby completly empties the breast. Remove your bra if it is too tight. Apply moist heat for 15-20 min before feeding. Begin nursing on that side. Gently massage the breast just behind the sore area while nursing. Try positioning the baby with the chin close to the cogged duct. Increase fluids.
Watch for an infection.... fever, chills, achiness. If these occur, see your doctor immediately.
Hope that helps.
~Rachel