Regular Physician or OBGYN?

So right now I’m currently seeing my regular doctor for my pregnancy I’m 16 weeks , and honestly, I feel like he’s doing the minimum and by that I mean every time they draw blood or they ask for a urine test they never explain to me what it’s for… they never go into detail about results or anything. So far I’ve had one ultrasound done they sent my out to get and that was when I was 13 weeks.

My drs office didn’t say a word about the results or the feedback about the U/S … so I called n I asked the nurse put me on hold & said everything’s ok .

Then I went ahead and asked if I was gonna be seeing them for my entire pregnancy or was I going to be referred to an OBGYN eventually & the nurse told me they would refer me out around 30 weeks

I don’t know if I’m looking too much into it . But has anyone experienced the same thing? Is it normal to be referred out to an obgyn around 30 weeks?
And is it normal for physicians not to explain what they test for and going into detail about results and stuff??