Just found out yesterday i’m having twins at 7 weeks.

Yesterday I went in for my first ultrasound to find out it was twins! Needless to say i’m freaking out a bit! One is measure a few days behind is that normal? Heartbeats are 123 and 140. Really hoping they will be okay ❤️ Can anyone tell me what kind of twins these are? I was in shock and not sure about the different kinds

. Thanks