What Can Cause Delay In Periods,milky Discharge,breast Tenderness,breast Tenderness,cramping,lower Back And Hip Pain?

Hi, may I answer your health queries right now ? Please type your query here...The first day of my last period was on Nov 25. I have done 4 pregnancy test, all negative. I am experiencing consistent thin milky discharge, breast tenderness, mild lower abdominal cramping on and off, lower back and hip pain, and gas. What do you think could be going on?