Please help

Went for 1st ultrasound, was measuring 7w 1d going off last LMP-US tech dated me at 6w 2d per measurement of fetus. No heartbeat was detected and the tech said that’s normal for how early it is and that I could come back next week or 2 weeks from my appt which was Monday July 1. The tech sent over my images to my OB, but the US images were dated at 6w 4d rather than the techs words of 6w 2d, they called me in saying they were concerned for no heartbeat. They attempted again only less than 48 hours from my appt on monday and tried to detect heartbeat but still weren’t able to find one and said it could appear as miscarriage. They also said since the images were dated 6w 4d that the baby should now be measuring 6w 6d as of yesterday but again, the tech said on Monday that I was 6w 2d? So everything feels so misleading and confusing on everyone’s end- including my dr saying the same. They weren’t 100% sure so they took my HCG levels through bloodwork yesterday and have me waiting until Saturday to go back for my bloodwork to see if the levels have risen at all. Can anyone give any advice or experiences?? I am stressed as it’s really not that long of a wait but if anyone has been through this, you know it feels like it’s taking forever. Please, anything will help, just want a peace of mind or to know what to expect if worst case.