Feeling so scared. I am 8 weeks pregnant and had my first ultrasound done Friday. My doctors office…

Feeling so scared. I am 8 weeks pregnant and had my first ultrasound done Friday. My doctors office called me today with the results and informed me that the gestational sac is not advancing as it should be. I am terrified because I had a miscarriage before this pregnancy and do not want another miscarriage. I am going to do blood work tomorrow to check my hcg levels. Has this happen to anyone?☹️