What Causes White Discharge?

Hi doctor....I had a baby 8 months ago and I'm only breastfeeding him...ofcourse he already started on fluids and I give him apple juice/water in his sippy cup. I still have not gotten my period. But then again I have not been protecting my self with condoms or nothing. I've notice white chessy discharge from my vagina. What could this be? DO you think I can be pregnant? Help?