Thinking about changing doctors

I've been thinking about this a lot for the past week while still waiting on my appointment that I made 3 weeks ago (which is finally tomorrow). My prenatal dr is the hospital/clinic (they're connected, which is something I love about it) only ob. It never once crossed my mind that he would be too busy for a first time pregnant woman who was told 3 years ago she couldn't have kids. But I've just been growing more and more irritated with the situation the longer I've been waiting. My very first ob appointment he didn't show up. I understand that he was busy, but every other dr in the practice has a fill in, except him, so I drove a half hour to an appointment to just turn around and drive back home because apparently his nurses don't call you when he's unable to make an appointment either. Now, this wouldn't have bothered me so much, I was able to make another appointment for 6 days later, but I had moved my original appointment ahead a couple days because I was cramping really bad and I wanted to make sure everything was ok. Having to wait another week, I wanted to switch dr's then, but I didn't. So when I finally got my first ob appointment, he spend what I honestly think was about 20 seconds doing a pelvic exam and pap, and then left. And now there's this; I scheduled my second appointment 3 weeks ago (it was supposed to be set for sometime last week), but the earliest appointment he had available was tomorrow. Really?!? I know he's busy, but he honestly has to have appointments scheduled 3 weeks out? He's a nice dr, but I just don't feel like I'm getting the care I deserve.