Confused about my U/S today!? Help pls! Pic included?

i really think your just earlier than you thought. that same thing happened to me. i went to the dr thinking i was 8 weeks and i was only 5 1/2. i worried to death but when i went back 2 weeks later, there was a heartbeat and a very small baby. but before that my u/s looked just like yours. just really a sac and no visable baby yet. try not to worry and im sure its fine.