Fetal cystic abnormality

Patient: Long shot but im hoping you can help. i have just had my 20 week scan and baby is happy , brain, heart ect fine and is active. However a cystic abnormality was found adjacent to babies bladder. it is 2mm aprox and is fluid not solid. it is not attached to anything and has no blood flow in or too it. i have been refered however am yet to recieve an apointment. it is my first child, i have no medical history and nor does the father. please help. my baby is happy at the moment but i am worried sick.