First sonogram at 8w1d

I had my first appointment today and had a transvaginal ultrasound done and was so excited to see my little baby! According to my last period I am 8 weeks 1 day today I measured exactly that! So I thought that was cool. I also saw my baby's heart fluttering/beating on the screen, except when we tried to hear it, it was really soft. The midwife said it was about 150-160 bpm but I'm not sure where she got that from other than seeing how fast it was fluttering on screen. 
​Has that happened to anyone?? 
​My next appointment is at 12 weeks and I can't wait!!