Liquid in sack

Hey went to gyno today I'm 3 months and he gave me appt next week due to to much liquid in sack. He said need a transvaginal to verify what's going on and said it might be many things including genetics. Gave me progesteron cus its my 3 time bleeding heavily. But gotta get some test done. Has anyone had this issue??? Any info that could prepare me for what's to come or give me peace of mind?.