My left nipple is starting to get quite painful when dd feeds

I did have pain the first month after having her because the left is a different shape to the right I've never had any issues with right

But now at 4 months its hurting again at the start of the feed when she latches and once she been on for a few seconds it gets better

She just started teething also and coming on and off because of distractions but the right side doesn't hurt so I'm confused

Lansinoh doesn't helping either