What will they see on ultrasound 7+3?

I had early ultrasounds at 4+1 and 5+6 (didn’t know I was that early). The first one they saw nothing at all, the second one they saw a 10mm gestational sac and nothing else. They told me to come back around two weeks late which would be Friday the 5th January. I would be 7 weeks 5 days. Due to work I can’t go on that day, only on Wednesday 3rd January when I will be 7 weeks 3 days. Will two days make a lot of difference? If I go on the Wednesday will they see a fetus/heartbeat?

Thanks