Hi ursy and welcome to HCM.
Ovarian cysts are common and most of them dont cause any symptoms. Usually it is found accidentaly. It causes symtpoms when become ruptured or torsioned. It is usually periodic and happens during ovulation. Pain is sharp and sudden in lower abdominal area. This fluid can be sign of ruptured cyst or intraabdominal inflammation
but also it can mean nothing. You should do frequent followups to evaluate size and enlarging of cyst. If there is any doubt of rupture, malignancy or fast enlarging it can be and should be removed.
Wish you good health.