Gestational sac a little ahead

Hi there!! I went this past Tuesday vaginally where I think I was around 5 weeks 4 days, they saw gestational sac and fetal pole. Gestational was measuring 6 weeks 4 days, 5 days later I went to an elective ultrasound and they found baby measuring 6 weeks 2 days right on track with my last missed period, I am exactly 6 weeks 2 days. My sac measured 7 weeks 2 days so grew exactly 5 days since my vaginal! Doctor said it was normal for sac to be a little bigger than fetus, is this true? I can’t remember with my first baby but once you have a MC you overthink everything. Babies heart beat was heard today at 122 BPM 🤍