First appt couldn't hear heartbeat

Hi all, just went to my first appointment today (last week had an ultrasound due to some bleeding, saw baby was ok and heartbeat was 160) so today my midwife couldn't get the heartbeat on the Doppler, she tried the internal Doppler as well and still nothing.... She scheduled me for an ultrasound for next Thursday(that was the earliest!) to make sure everything is ok and check the bleeding since I am still bleeding brown old blood. Has this happened to anyone, not hear the heartbeat the first appt? I'm going to be be freaking out until Thursday... Midwife didn't seem too concerned since last week the heartbeat was strong....😕😕😕