My doctor told me i was having twins when i was 6 weeks. She ordered a second ultrasound, BUT she didn't tell me she only saw two sacs and only one baby until my 2 ultrasound when they still didn't see another baby at 7 weeks. im now 11 weeks. She said now I'm not having twins, why would she say i was having twins when she didn't know for sure? has this happened to anyone else? Ive heard of the vanishing twin, is it possible they just couldn't see the second baby?