What Causes White Vaginal Discharge While Trying To Conceive?

My husband and I have been trying to get pregnant for about a year now and nothing yet. This month feels different I am to start my period tomorrow but I have been have different symptoms and I don’t know if I am pregnant? What is happening is for the last few days I have been having white, clear discharge vaginally and I have never had before. I have been having cramping, sore nipples and dizziness. What does this mean; am I pregnant?