Hi and welcome HCM.
It can be another follicular cyst
but also many other disorders such as endometriosis
or pelvic infections. YOu should do ultrasound
again to evaluate your ovary if pain persists or progresses. Pain can always be provoked by sexual intercourse, but this isnt a reason to avoid it. Take some standard painkillers half an hour before intercourse. If nothing is helfpul then hormonal
therapy may be started,but go step by step and I am sure everything s gonna be fine. Wish you good health.