5 + 4 weeks and empty gestational sac

Based on my positive opk I estimate myself to be 5+4 or 5+5 weeks pregnant. By LMP I am 6+1. I have a history of recurrent miscarriage, and due to some pink spotting I was given a transvaginal ultrasound this morning. They only found an empty sac, no yolk or fetal pole detected. I have to wait 2 weeks for a repeat scan and am absolutely beside myself with worry. Has anyone had anything similar and seen a baby at the next scan?