Your baby may not be "latching on" correctly. "Latching on" refers to the way your baby attaches her mouth to your breast. If she has latched on properly, she'll get a good flow of milk, and you won't get sore nipples.

You can help your baby latch on by touching her lower lip to your nipple as she roots for your breast. She'll turn toward the side where she is touched. Then, when her mouth is open wide, lift your breast with one hand and pull your baby close to you. Her mouth should attach firmly onto your breast, not just your nipple. You may also try changing your position for nursing your baby. Or start nursing on the side that's the least sensitive for you. That way, your baby's strongest sucking happens before you switch to the more sensitive side.

Related Link:
Read About Some Common Breastfeeding Questions and Concerns