It began yesterday, out of nowhere. Only my right boob on the right side is so sore and tender, it even affected my sleep a little bit last night. I've never dealt with sore breasts when due for my period, which is due in a little over 2 weeks by the way. The last time I had sore breasts was when I was in the first few months of my pregnancy 2 years ago but it was both boobs. Not just one side of one boob. Thoughts?