Hello! I'm in my second and very long-awaited pregnancy; I'm 8 weeks a…

Hello! I'm in my second and very long-awaited pregnancy; I'm 8 weeks along. I've always had low blood pressure and low hemoglobin. I went to my local (district) gynecologist to register for prenatal care, but they refused, arguing that registration is done from the 12th week. Please tell me, can't I register now if I want to? And is a gynecologist's referral required for the first ultrasound, or can I have it done on my own? It's been 10 years since my first pregnancy and a lot has changed, I don't even know what to do anymore )))