Pregnant with twins?

Lee

So I had a blood test today and my ob said my hcg levels were pretty high for only being 5 weeks along, she didn't tell me my hcg number even though I asked her twice but she instead proceeded to ask if multiples ran in my family. Should I be concerned? First ultrasound is scheduled for two weeks out, would they even be able to tell if I'm having twins by then?

Side note: I'll be switching OB's