What Causes Chunky White Odourless Vaginal Discharge?

the beginning of my last period was Dec. 14. I had a doctors appointment Jan 6th to begin birth control. while there I tested negative for pregnancy. I have not yet began taking the birth control medication as I was waiting for my next period to pass first. my period still has not come yet. I had a pregnancy test taken today (Jan 15) which was negative. I noticed some chunky white but odorless vaginal discharge today. should I wait for my period to begin taking the pills, or can I start them now? and what does the discharge indicate?