Why are my boobs sore after period?

So I have gotten my period 2x this month. The first time was light/medium flow. Then I got my period again 2 weeks later and was a heavier flow. 8 days after I now have sore boobs… when I’m normally have tender breast a week right before my period is due. Took a pregnancy test and it was negative. I have PCOS But having my period 2x in one month is NOT normal for me. I’m usually either always late!

Could I be pregnant? I don’t track ovulation. I gave up on that.

Anyone else experience this?

Thank you 🙏