My baby was measuring correctly but they couldnt see a heartbeat at 8 weeks what are the chances of finding a heartbeat later on

Everything looked normal , baby measured on time but when I asked about the heartbeat she couldn’t find one. I was told since I’m not bleeding I’d need a dnc to clear everything out, I asked if I could have a week to see if baby would pass on it’s own and I’m at that week mark and nothing. I’m still having pregnancy symptoms such as sore breasts on and off nausea , light cramp here and there and pinching. My husband wants to get another ultrasound just to make sure they didn’t miss something and maybe baby is actually alive. What are the chances of not finding a heartbeat at 8 weeks and seeing it later? I know I should move on but until this baby is out of me I can’t give up hope 😞