How Can Labial Ulcers With Itching Be Treated?

Two day ago i woke up with 4 little ulcer looking things very close together almost touching but completely separate (not bumps) on my labia . They are itchy but I do not itch them Today i took a look down there and they seem to be growing together to form one big ulcer. I am confused because i have not bee sexually active in about 2 months what can this be I ve looked up symptoms of herpes and images and they look nothing like that my symptoms and look of it look more like a chancroid but then again i have read they are uncommon in the US