Twins or not????

Okay so today..I had my first ultrasound. They couldn’t see very well doing it through the abdomen so I ended up having to do a vaginal one. As soon as the nurse did it I saw a baby and a heart beat, then she scanned the rest of my abdomen and when she moved left there was a baby on that side...also a heart beat...I asked her is that the same baby??! She didn’t answer me and kept looking back n forth and every time she scanned back n forth there was a baby on both sides...separate sacs. She said it’s definitely twins but she wants the doctor to come in and look. Doctor comes in, looks and says no she thinks it’s just one baby but because I’m only 9 weeks it’s hard to tell for sure so she’s not going to confirm it...when I got my ultrasound pictures I have one picture of the baby measuring at 8W 1D and a separate picture baby measuring 7W 1D. And the two pictures, one baby still has the yolk sac and the other baby picture there’s no yolk sac anymore...they are wanting to do a 4D ultrasound in like 4 weeks to look again. What do you guys think of all this?