i have always had white discharge, the only time i got other discharges was when i was ovulatig that i got the EWCM.
It could be a sign that you have a yeast infection. Have you noticed any itching, even being mild, or any odd smells or pains? If not then it's probably just normal cervical mucus. Depending on when the last time you had intercourse was there is a small chance it was too early for the blood test to register a positive result IF you were pregnant. But considering you just came off your period it's highly unlikely. You can always go to your gyn and be checked to see if you have a yeast infection if you feel it's not just normal discharge.
I am unsure about the chance of this happening in a non pregnant person but I know I did experience this during pregnancy in the beginning.
It could be normal without an existant pregnancy however I have never experienced it. It may also happen with an std, I have heard of it but again am not sure.