What Causes Left Side Pain In Abdomen And Watery Discharge?

hi i am 27 yrs old and 5 feet 7 inch tall with good health.i am married woman.and now trying to conceive.today i am having pain in my left side of lower abdomen,with watery discharge from vegina.now in evening transperent and thick discharge is coming.what could be the reason?i had my regular periods on 10 of may.