Itching & Burning during and after breastfeeding?

I have been EBF my 3 week old daughter with no issues outside the expected cracked nipples and soreness in the beginning. Just as I was healing she started to feed a lot more frequently. I noticed that my left breast will itch and nearly burn when she's nursing. Then it burns for a little after she's finished. It's an odd sensation and I figured it was just my "let down". It doesn't happen often or nearly as bad on my right breast, if at all.