No heartbeat. Miscarriage??

So the thing I dreaded the most happened today. Went for my first pregnancy ultrasound today. According to my LMP, I should be 8 weeks and 4 days today but ultrasound date is 7 weeks 1 day. That’s a huge difference considering that I have a regular 28-30 day cycle. No heartbeat could be found either. It was so disappointing. Doctor wants to do another ultrasound a week from now to see if any progress is made. But from the way things are, I feel this is a miscarriage. Has anyone gone through a similar situation but went on to have a successful pregnancy? I don’t want to get my hopes up and prepare for the worst but still would like to know if it’s still possible to see a heartbeat next week. Can things turn out to be better or is it a lost cause? Pls give frank replies..thank you 😊