When did you get blood tests to confirm your pregnancy?

with my last pregnancy I found out at 5 weeks but couldn't get into a gp until 12 weeks because I was a NEW patient and we had moved..... So I never got a b/t until I started to miscarry, so I'm wondering....

This time, obviously I have taken numerous pregnancy tests but when should i book my appt for a blood test ? At how many weeks? And when is the best time for a dating scan ( for EDD ) although I'm pretty sure....