Confused/worried

Hi everyone, going to try and explain this as best I can, I had a miscarriage 5 months ago and recently found out im pregnant again on the 25th september (2days after Period was due) I booked a private scan and according to LMP I should of been 7w-1d but because I have 40 day cycles I was only measuring 5weeks and 5 days, which I was expecting, as according to this app I should of been 5w4d and ovulated around the 8th October, but because there wasn't much to see on the ultrasound I was asked to reschedule in 7-10 days. Which I did. They booked me in 8 days later which was today, so my concern is this....according to my last scan on the 3rd October which measuered 5weeks 5days, I should of been measuring 6weeks 6days today but was only measuring 6weeks 1day, im a little worried my baby isn't growing properly or maybe stopped growing. anyone had similar a similar situation?