When should I see a doctor?

I just took a clear blue test (well two of them) and they both said positive 2-3 weeks. I'm really excited and so is my SO. A big question is when should I go in to see a doctor????
I don't want to go into late to see one. And is there anything I should be taking to prepare? I'm a bit nervous because it's my first pregnancy..
So any advice would help!!!!