Hi, your cyst is in all probability a benign endometriotic cyst. Endometriosis
is a condition wherein endometrial tissue is found at sites other than the native uterine cavity
. It is a common cause for dysmennorrhoea and menorrhagia
. My advice to you would be to visit a gynecologist who will decide whether something needs to be done according to your age(you have'nt mentioned the same). On the other hand, if it is an abscess
(unlikely at the site; evaluation will include presence of fever, pain and source of infection), you must undergo an emergent evaluation and therapy.