Abdominal or internal ultrasound

So I’m 8 weeks today according to my lmp and paid privately for a private scan. They did an abdominal scan and baby measured 5w 5days and we could see a flicker of a heartbeat. I asked the technician would a internal scan be more accurate but he said no they are the same. I have an appointment in the epu that I had arranged prior to this as I had a miscarriage last year. I can’t help but worry this pregnancy is going to end the same way. Any advice?