HCG 24000 but baby not detected

Update: It was ectopic. Had emergency surgery last night. It ruptured so I lost a tube. Went to my OB Tuesday she told me she didnt see anything in my tubes or ovaries so the surgeon was confused as to how she didn't see it with it being as large as it was.

My levels are at 24000. But when I had my ultrasound I was told my uterus lining is thick, but she didn't see a baby. We've miscarried twice and have been trying for awhile. I'm not sure what to think or feel. Any advice? Or anyone have a similar situation? I also have PCOS and EXTREMELY irregular periods. Help! I'm losing it.