Possible MMC

Victori

My baby girl is 11 months old and she is breastfed and I have not had a cycle. I tested positive Feb 4th, and got blood drawn and HCG was roughly 20,000 which put me roughly at ~6 weeks. I went for Ultrasound today and heartbeat was not detected but could see gestational sac and yolk sack and measured roughly 6w5D and HCG was 36,000. Said to come back for follow up labs. Should I prepare myself for the worst?