Nipple Pain

So recently I’ve been experiencing some pain whenever I touch my nipples, and I’m not quite sure why!

I’m almost positive I’m not pregnant (had my period last month and haven’t had sex since New Years so 99.9% sure that’s not the case haha). My period is due in like a week, so I was thinking it could be PMS, but I don’t normally have any PMS symptoms involving my boobs or anything! Maybe it could be an issue with my bra?

I’m not really sure, and it’s only my nipples that hurt when I touch them, not my areola. Any tips on how to stop the pain?