first appointment

hi I am 5 weeks and 2 days pregnant and am really excited. When I found out I was pregnant 1 week ago I rang the Dr's surgery to book an appointment as advised by many sites only to be told by the receptionist that I don't need to see the doctor and need to self refer to hospital (i was a little surprised by this but then this is my first pregnancy). Anyway yesterday I received a letter for my first appointment and ultrasound 20th October where I will be 12 1/2 weeks..is it normal to wait till this point to see anyone medical?