Couldn't find a heartbeat. 😫

I'm only 5 weeks 6 days and today I got my first ultrasound.. the doctor said everything looks perfect but she couldn't see any heartbeat. She said she's not worried about it because it's still so early so I'm going back for another ultrasound in two weeks.. with my last pregnancy I saw the heartbeat at this time so I'm just really worried and anxious. 😔 we wanted to announce this weekend but I don't really want to now.

Is it common to not hear the heartbeat this early? Has anyone went through this? I'm trying not to freak out but I am.