What can I expect at my first appointment?

I had a positive pregnancy test on Friday and I called to make an appointment for next week. I would be about 4 weeks along. However, I am having non-stop, persistent sharp pains mostly on my right side, but some on my left at times. I am concerned it's an ectopic pregnancy.

What do you think I can expect? Will they send me off to find a lab to get blood work, or to get an ultrasound?

Will they be able to determine an ectopic pregnancy at 4 weeks on the ultrasound? I'm soooo scared and anxious and impatient.