Nipple Phenomenon

Good afternoon!

Today I noticed my nipples looked swollen, and upon further inspection the “pores” on my nipples seemed larger or more open. When I squeezed them, a very small amount of whitish discharge came out.

I have never been pregnant but my husband and I have been trying for over a year. My expected period is in 4 days.

I’m confused and a little worried about what is going on. Has this happened to anyone before? Should I be concerned? I do self breast-exams regularly and haven’t noticed anything else out of the ordinary.