HELP:: 4 week ultrasound??

Jasmin
So today I went into planned parenthood to confirm my pregnancy-it came up as positive! Then they were asking about my symptoms and I said that everything seemed normal (my first pregnancy) but I did have on and off cramps on my lower abdomin...(pain level maybe 2/3) intermittently.
Then they made an appointment for me today to a different facility and get a blood test AND ultra sound.
No one I know has ever been refered to an ultra sound this early.
I'm getting very scared any advise would be helpful.