Girls, help?

Girls, help? Start of menstruation 13.02. According to calendar (based on menstruation) shows 9ne1d According to ultrasound first it was already delay. Embryo saw, at 3-4 weeks they were setting. At the time of the menstrual cycle 5-6 weeks. According to the second ultrasound (I went to check the heartbeat) there is no heartbeat. They write that frozen term 5-6 weeks. The PA was 21.03. Can it be due to late ovulation, for example such a spread in terms according to ultrasound and by months? And wait for the heartbeat? Or should I wait for cleaning already? Has anyone