There doesn't seem to be a set thing. I had bloods done when I told the GP we were TTC. But once pg, the OB sent me for the same set of bloods anyway, even tho the others were only really a few months old.

I ended up having a viability scan at 8 weeks as I was having some bleeding, but I think a scan at this stage isn't standard unless there's hints of problems.

My first OB appointment was at 12 weeks, where he did a quick scan himself just to basically measure the baby and make sure blood was flowing through the chord etc. But we opted not to have the NT scan, as we knew we wouldn't terminate for any reason anyway.

I think the important scan is at 18-20w where they do all the measurements and make sure the baby's organs are developed ok, like the heart, the brain, the kidneys etc.

I'm not scheduled for anymore scans at this stage. I think if you're having a problem free pregnancy, they just let nature do it's thing

I also just had a blood test for glucose levels and blood count (28weeks). That's a standard test too I think.

Don't know if any of that helps you at all.