What Causes High Prolactin Levels, Breast Soreness And Nipple Discharge With Bleeding?

Hello, I am a 21 yr old female and recently i did a blood test which showed that my prolactin levels were a little higher than normal. this level is not very high but i noticed that my left breast felt very sore and i am due to have my period so i thought it was just sensitive but then i squeezed my nipple and found that some white thick stuff came out then some clear fluid mixed with blood came out after. The soreness has decreased now. I am worried. what does this mean??? also i smoke occassionally does smoking have anything to do with this??