Nipple pain?

My nipples have been hurting pretty bad this past week, but today they look reddish/purpleish? And slightly bigger? (Very slightly) I know I'm suppose to start my period this in a week or so, but idk it's been hurting pretty bad. And not like the bumpy part around it, but the actual nipple part.
ALSO there always seems to be white stuff in the center of them, but I've never been pregnant? This has been happening for a little over a year.