Can't stop crying.

Went in for my first ultrasound today at 7 weeks and 3 days. I've been really anxious through the pregnancy as I have no morning sickness or anything other then sore nipples and Ive always been worried I'm just gonna wake up and it'll be gone. Went in today and she can't see anything, zilch, nothing. She said to go back and see my doctor and she'll probably refer me back in a week but she doesn't seem confident in anything :(