Left side

It hurts only when my baby nurses on my left side, my ride side I don’t feel a thing

She is 4 weeks old so I’d assume it’d get better, I literally cried yesterday letting her nurse on that side. And I wouldn’t say every single time but majority.

I’ve checked her latch, when I take my nipple out it looks perfectly normal no sign on my nipple from a bad latch, I tried all positions on that side and nothing seems to help but not sure what else i can try or what can be happening?