some let you "graduate" at 8 weeks. others at 12. it depends on their philosophy, and if you are considered a special case, (previous MC, advanced age, low progesterone) etc. i would stay with them. you get more care. at 8 weeks all my ob does is have you fill out papers. there was not any bloodwork or scans until 12 weeks at my OB.
I agree that is what my clinic is doing as well. I may be able to get referred a little earlier maybe 11 weeks because my clinic is not in my city. But my first prenatal is with my clinic.
This is the same protocol at my clinic. I think it is pretty standard to stay with them thru first trimester