I get infrequent blood spotting every month before my period with a week or 2, i did a urine sample test and the result is sterile pyuria, what's this?

Sterile pyuria: Means presence of white cells in the urine in the absence of bacterial infection on culture. It could be due to kidney disease, autoimmune or systemic illness, tb, medication side effect etc. Infrequent spotting could be from hormonal imbalance, ovarian, thyroid or adrenal problems. Take care! .http://en.m.wikipedia.org/wiki/pyuria.