Thanks for your question as there is swelling on the left side of your vaginal area the major cause which causes swelling in your vagina may be bartholin’s cyst.It is cause because of the obstruction that is there is opening of the Bartholin gland which is their on each side of your vagina. There is more chances of getting abscess formed if the fluid in cyst gets infected which increase the chances of infection.This really matters because the treatment for this depend on the size of the cyst and depends on the abscess is present.As there are two types of cyst as there is small cyst and large cyst.If abscess is present then small cysts will require sitz bath whereas larger cysts will require antibiotics and require surgical drainage. According to me I would suggest you to go for a doctor and go for the checkup required in this symptoms.Take care