Fetus heartbeat not audible.

I had a scan at 9 weeksplus. From the ultrasound scan, the fetus was seen flickering. I was told before that the flickering was the fetus heartbeat and that was at 6 weeks. Back to my scan at 9 weeks, the gynae said that heartbeat was not obvious so she did the transvaginal scan. The heartbeat was not detected. Im kinda confused because i thought that the flickering fetus was actually the heart was beating. Anybody has or is experiencing smthing similar? I was just hoping that the fetal heartbeat can be detected the next scan which is in a week's time. Please share :)#firstbaby #advicepls #hopingforababy