1st scan...no heartbeat

Went for our 1st scan today, we saw our little "chip" but couldn't see or hear a heartbeat. 😥 they said it could be that I'm earlier than we thought and we should come back next week for another scan. Now we are both freaking out. I know this can be normal and I have read many other people post about this same situation,  this is our first child and we have both waited so long for this.  I'm just hoping the nurse is right and we are just early then we thought.