Annoying doctor.

So i am High risk due to tearing all over my uterus and a partial septate. (Basically my uterus looks like a heart) But it can be dangerous cuz baby can run out of room very quickly and my uterus cant stretch as far as someone elses. Anywayyy. My doctor has yet to check my cervix or measure my belly. When do they start measuring bellies to see how tall & how much baby weighs??? Im getting worried. I want to know that he’s growing okay and all that fun stuff. Im a FTM if u cant tell.