I blister on vagina. Itching and burning. No abnormal smell, no abnormal discharge. I am worried. Could it be HPV?

Possible herpes. A blister like that is more concerning for herpes than HPV. I would have your doc check it out in office at first available appointment to see what it truly is and appropriate treatment for it. Primary genital herpes may require antiviral medication and warrants a trip to the doctor. Avoid unprotected sex until it is properly diagnosed (condom mandatory or abstain)