I think it really depends on your situation, if you are going through a hospital/ public then 12 weeks seems to be the time... if you are going privately then they do things differently sometimes, and the OB's themselves have different structures individually... so its best to call if you are going privately and find out from them, if you have concerns i.e. previous m/c or endometriosis/pcos then they will definately want to see you earlier... and you most likely will have a scan earlier as well...

Christy