4 weeks behind?

Went in at around 10 weeks (irregular periods and was on clomid) and measuring 6 weeks with only gestational sac no yolk no fetal pole, and labs coming back at 5000. Should I be worried? Following up with my doctor in a week but we’ve tried so hard for this baby I’m not sure if I should give up hope yet or not. Any advice or ladies in the same boat before? Thank you xoxoxo also no bleeding no cramping no pains etc.