Twin Question

Allison
Hey all! I had my first transvaginal ultrasound at 6w1d. (Thought i was 8 weeks..I was way off!) Not much is seen at 6 weeks. We did see a flutter of the heart but not much else. I have had a hellish month with sickness and i'm gaining weight rapidly. My lower abdomen also seems big already. I keep having these dreams that i'm having twins. If I was having twins, would the doctor have been able to see that at 6 weeks? This Monday is my next appointment at 10 weeks exactly. Hoping for one baby and so nervous its going to be more. Any ideas? (Here's my 6 week picture)