Thanks for the query.
There is possibility of some infection or folliculitis
, that might have led to ulcer on one side.
And that ulcer might have caused contact ulcer on the other side at same spot.
Immobility, warm and humid areas will encourage these type of lesions.
So better to get examined by the gynecologist.
If she recommends you can go for swab culture and sensitivity from the ulcer.
One course of antibiotics and local anti - inflammatory creams can help in curing the lesions.
Try to change inner wear frequently and keep the area dry.
Sitz bath can give some relief.