What does it mean when i'm std free but have a milky white discharge accompanied by lower abdomen pain back pain heartburn and headaches could this be a sign of early pregnancy?

Bacterial vaginosis?: We all have bacteria living in our vagina. Sometimes "bad" bacteria grow there, which can cause some discomfort (often not though) with milky, yellow, greenish discharge, sometimes with fishy smell. This happens more with multiple partners, douching, and smoking. Lower abdominal and back pain are more concerning for uterus or colon problems, and heartburn is unlikely related. Please see OB/GYN