Thanks for your query.
After two ultrasound
confirming that there iso heartbeat, I am very sorry to say there is no scope for a heartbeat now.
Please be patient and accept the reality.
Go along with the medical management advised to you.
Also, please have a complete evaluation of the reasons for this intra uterine death.
Have complete biopsy
of the fetus and placenta.
Rule out genetic causes, infections, blood group incompatibility
, autoimmune conditions, abnormalities of uterine size and shape etc.
Have a complete work up after consulting a Genetic counsellor.