Late and sore nipples (no pregnancy)

Hey, guys! 
Sooooo I am 4 days late. Usually my period is 32-36 days. It is day 40 now. But there are some strange things about this one:
1. Just around my fertile week I got a little bit of brownish CM
2. I have sore nipples sometimes. 
3. Yesterday, when I was trying to stretch in bed in the morning I felt something down there, like it wasn't prepared for a stretch. Difficult to describe. 
During this month also started taking multivitamins for women (with folic acid for e.g.), but they are not prenatal or whatsoever.
And also I have been emotional lately. Even had a quarrel with my boss and cried. 
Any ideas what could it be?
Thank you in advance!