What Causes A Shadowy Area Underneath The Skin In The Areola?

I am a 46-year-old perimenopausal woman with two children ages 9 and 12. No family hx of breast ca. I recently developed a shadowy area underneath the skin in the areolar area which produced a brownish watery liquid when squeezed. Last mammogram was wnl performed in June of 2010. I have an appointment with my OB/GYN tomorrow and a mammogram and ultrasound scheduled for next week. A little freaked out...a little reassuranc would help. Please note that I do get hair growth in that area and have been known to pluck the hairs. Thank you.