Twins oh my! 👶👶

Evelyn • I am 32 yrs old. With my DH for 10 years. TTC #3
I just found out I'm pregnant with twins today. I'm exactly 6 weeks. The tech saw one heart beat and the other was too small to detect. She said she saw a flutter on the other one but she said it was too early to tell. Is this normal? She said that sometimes one twin measures further than the other too??? Please help I have no clue when it comes to twins!