What Causes Cyst In Labia Majora?

hello, i'm 23 years old ( virgin) i've noticed for the past few months that i have a sort of a ball inside my left labia majora (painless and does not bother me at all but it's so obvious when lookin to my naked vulva), so i looked it up on the internet and found ( from the descriptions of other women) that it might be a bartholin gland cyct. what do you think??? and i've read that green clay can be used as a natural remede in this case!!!
pleaaaaase give me your advice
thank in advance.