Nervous for ultrasound!

So Thursday is my first actual prenatal on appointment. I was seen for an emergency appointment because I thought I had a uti and they wanted to see me. Because I was there they brought out one of their bedside (which they said was an older machine) and did a transvaginal ultrasound. At that point I was 6w2d. They said that I was measuring a little behind but we would see more at my next appointment. So now, on Thursday is my appointment. I'm nervous!! Im praying to see a heartbeat. On Thursday I will be 8w5d. Anyone measure behind at first and catch up  for the next ultrasound?! I just want everything to be okay!!!