Does this early scan show twins?

I went for a scan today and I put myself at 5 weeks 4 days an these are the pics i was given. originally the sonographer measured up the top white blob as my baby, then said wait this might be your baby and didn't seem sure. She left it is as the bottom one but identified all the features on top one eg fetal pole, yolk sac etc and could not tell me what the top one was instead. 
Was just hoping from some input from other mums as to their opinions, I know it's early but should I be bracing myself for twins??Or if its not twins any suggestions as to whats going on? Any mums had anything similar?