Welcome! and good luck!! Dont be nervous ots actually really exciting!
Here is where it explains what a ob is.
http://www.healthcommunities.com/pregnancy/what-is-obgyn.shtml
ohh forgot if you are 8 weeks when u go in you may get to hear the babys heartbeat however some women dont get to hear that early. aldo I forgot that my ultra sound was a vaginal one. My obgyn likes to do a vaginal ultra sound when your eary along because you can see mich better. The vaginal ultra sound is a small wand they insert inside your vagina and its painless. hope this helps!
On my first appointment I had an ultra sound where theu confirm how far along you are and give and estimated due date. I was sent to the lab for blood work which checks for hiv, hepatitis, and other stuff. dont worry its typical testing as they need to know these things. They also did a examination and swab for chlamydia and this is also just procedure. They swab your cervix to get a culture to be tested. Dont worry that wont hurt. She also will go over your history and ask questions such as if you have had any bleeding etc. Dont worry hun ots all basic stuff :) btw congrats on your pregnancy!