Breast discharge

Natalia

So I haven’t breastfed in 3 years & lately my breasts have been sore, I️m not sure if im pregnant yet because I haven’t taken a test, I start my period in a week(is that too early to detect if I am?) & I noticed some crust around my nipple. So I squeezed to see if anything would come out of I️t & there was a clear, thickish discharge. Any idea on what this could be??