No heartbeat at 8 weeks?

My doctor told me she couldn’t find at heartbeat at 8 weeks. I’ve had no symptoms of miscarriage. She wants to do a D&C as early as Tuesday (in 4 days). I feel like everything I’m reading says to wait 10-14 days and do a second scan to be sure the pregnancy isn’t viable. Should I get a second opinion or push back with my OB? I don’t want a risky surgery until I’m 100% sure it’s a miscarriage. Any advice is welcome.