Girlfriend is sad she can’t hear heartbeat this past ultrasound

Hey y’all. I just found out a couple weeks ago that my girlfriend and I were expecting a baby, she just had her stomach ultrasound today and was devastated to learn that there’s no heartbeat, we assume she’s 7 weeks but we don’t know that for sure she has her vaginal ultrasound next week. Should we be concerned if we don’t hear a heartbeat then?