2 cm ovarian cyst, left hydosalpinx. gyn treated with antibiotics. will it go away? never had std, why did it occur in the first place?

Hydrosalpinx: Pelvic inflammatin can occur with non STD bacteria as well and is typically less severe than the type associated with an STD. In addition, some women have been exposed to chlamydia and took an antibiotic that treated it without knowing it. This is called silent chlamydia. A chlamydia trachomatis IgG can be ordered to see if that is the case. This is a blood test.

Probably not: A true hydrosalpinx is unlikely to go away, but if this only is based on an ultrasound exam you cannot be certain the diagnosis is correct. You can have an asymptomatic STD that damages the tubes. Chlamydia is a common culprit. Ovarian cysts, on the other hand, come and go with your cycles.