If you got a ultrasound up the woo, could they tell if it was more than one ? Just Wondering.

got an ultrasound at 7 weeks 1 day up there like they stuck this thing which was very cold up my woo and I was a little confused because I didn't think that was possible but they didn't let me hear the heartbeat neither so I was just wondering. They did say the baby was healthy and had a strong heartbeat though. Personally thought that was so unfair, they heard it and I didn't.