Sonoline b fetal Doppler

Joy
Ok so I finally got one of theses Dopplers. After like 3 tries about 30 mins each I finally found baby's heartbeat on Friday. Since then I haven't been able to find it. I'm 9 weeks 2 days. I know it's early but I have had 3 miscarriages and haven't been this far.... I'm blessed to have been able to find it and blessed that I'm this far. Anyone else experience finding the heartbeat then couldn't?