7 wks 5 days with twins. Need opinions please.

So due to multiple miscarriages I worried when I found out I was pregnant. Last month I set up a free u/s @ pregnancy center nearby so I bc would see the baby sooner but they changed the date which ended up being this last Monday, 5 days after regular Dr u/s. Since bf couldn't go to one last week, I kept the appointment.

Well they only did a transvaginal last week which I thought was odd. They found 1 baby with heart rate of 123 bpm.

Monday's u/s they did an abdominal first. We saw two almost immediately and could visibly see both of the hearts moving. When she did the transvaginal she tried getting measurements and heartbeats of both but was having a hard time as one kept hiding. She did get 2 heartbeat readings and measurements which she said might be off as she's not very familiar with twins. One heart rate was 150 bpm and second was 151 bpm. Would it be odd to say that the heartbeats were both from the same baby? Or is it possible for them to be that similar??