Transvaginal ultrasound

Hi, so I live in the UK and I found out I was was pregnant and went for a private early scan about 11 days ago and she done an ultrasound on me all was okay and you could see the heart flicker she dated me as 5 weeks 4 days that’s fine so I then started spotting very translucent light brown more mucus tbh but this lasted about 5/6 days, but I was worried (1st time being pregnant) so I called early pregnancy clinic in the hospital and they brought me up and done a transvaginal so she was finding it hard to find the pregnancy and then finally she found it BUT the baby was nestled into my uterus wall but you could see it and the yolk sack and all but the problem is she couldn’t differentiate if it was the heart fluttering or my uterus pulsing 🙃 so now I have to wait 10 days and I’ve to go back up again and she’s going to repeat the process BUT this is what I’ve wrote this about why didn’t she do an ultrasound to check another way? Now I’m sat at home worrying and preparing myself for the worst for 10 days? I’m so confused. Alls I’ve done is cry and put myself down.