Checkup prices

As a FTM and a very paranoid person, I always find something to be worried about in my pregnancy. Now being due in 3 weeks and reading all the scary stuff here about what that can go wrong, I really want to know I can get checked at any moment to make sure it goes fine. In my home country, all the checkups are super cheap (at least they were for me always, as I had a good income there) so I'm used to just go in for any small reason. Now in US the situation looks very different. I've never been to an ER, only seen my OB at routine appointments. I understand the price for a checkup in the ER or the delivery section in the hospital should probably depend on the place and insurance, etc but still, how expensive is that in general?