Ultrasound #2 not even 7 weeks

So went in for U.S. at 5 weeks 6 days. They saw fetal pole which measured big at 6 weeks 3 days. And yolk and gestational sac which measured 5 weeks 6 days which is more accurate. However no heartbeat which is more concerning if i was actually 6 weeks 3 days. Anyway midwife called today and recommended another U.S. this Friday to try and find heartbeat. Also have a corpus luteum cyst causing a fair amount of pain but no bleeding or spotting. Just so terrified I won't see the little heart flicker!