first time, foreigner in the US w/o established ob/gyn and worried I can't be seen soon

I know it's very early but I'm 4weeks2days pregnant (dpo16) and the band on HCG test has been increasing in intensity - so far so good. 39yo, history of endo and infertility - trying >2 years (actually I was undergoing egg freezing in a private clinic now to buy me some time, but then I conceived naturally by surprise, we've given up on the idea that I will ever be able to conceive naturally).

I'm foreigner in the US (I got employer green card two years ago), I have HMO health insurance through my employer and my network includes academic hospitals. My husband is foreign too so we are a bit clueless on how to navigate the system.

I gave my network a call, and they told me first appointment can be the earliest in 3 weeks and two days i.e. I'll be 7week4days along, and I will only be seen by a nurse at this first time and they MAY do an ultrasound. I am honestly quite shocked - I expected that I would be called in by 6 week and seen by actual doctor. Is this normal? Is this how this is supposed to be?! Can someone point me to a resource of step-by-step what to do and to expect?

They didn't advice to take prenatal vitamins even on anything, didn't ask me if I am taking any medication that I should stop... NOTHING. I mean I know to take prenatals but, I expected a lot more.

Should I change my insurance to a PPO? Will that help at all? My open enrollment window is closing in 7 days and I need to act fast.