Should I have anything to be worried about?

I went to my dr appt and I’m 13 w 1 day and it took the dr like 3 minutes to find the heartbeat and once she did it was there for like 3 seconds and then she said ohh the baby must’ve moved on me but the baby sounds good! Idk at 8 weeks we heard the heart beat and she told us the heartbeat rate and this time was just so quick and we didn’t get to find out the heartbeat..

Also a little disappointed she said we won’t be doing the anatomy scan until 21 weeks.. I’m hoping at our next appt (17 weeks) we could talk her into doing it sooner!