What is going on!?

y

Ok so last month before AF arrived my nipples seemed tender and my boobs felt kinda heavy. Thy NEVER hurt. Well AF ended up arriving so not pregnant. And yes I took a test because it was a day late and it was negative.

Well now a few days after ovulation this month and they are coming back to being tender.

What's going on!? I know I can't be pregnant yes since it hasn't been long enough since I ovulated (got a positive OPK on Monday the 18th)