Bump under vaginal skin (inner labia)

Hi I had pain on one side of my labia after my period. It hurt when I touched it. It felt like a bump. I put antibiotic cream. The next day it was burning the skin broke, it was one dot like a pore. I put cream for another day...the third day it disappeared. Is this normal? Could it be my soap, pad or something else....it healed too fast to think it was an STD. What could it be?