Thanks for writing... this is a great question. From reading the brief description you provided, it sounds as if you have developed a specific phobia toward the doctor's office(s). And one of the things that drives the phobic reaction is a fear of being afraid (or, as you mentioned, the fear of having a panic attack). These conditions as actually pretty routine to treat, although you have to trust me here...
If you were a client, we would do a technique called systematic desensitization. I cannot go through the entire process here, but I encourage you to dig around and do some reading on it. Here are the basics:
(1) We create what is called a stress (or fear) hierarchy. When completing this task, we would assign "fear" values to an ascending list of fear-evoking situations involving the object of the phobia. In other words (that got a little wordy - sorry!), perhaps merely talking about the doctor would be assigned a value of "10." Then, looking at pictures of people in the doctor's office may be a "20." Pulling into the parking lot may be an "80." Getting out of the car and going to the door, a "90." This goes up the pole until we hit a "100," which is actually walking into the office and checking in.
(2) Now, once this is established, I would train you to relax. We would go through progressive relaxation techniques that involve deep breathing and mental imagery. I would teach you to feel the difference between being tensed and relaxed, and then train you to get into the relaxed state.
(3) Now here's the crux of the technique (and this is based upon a psychological/therapeutic principal called "counterconditioning" which basically says that you cannot be STRESSED and RELAXED at the same time - so we make it such that relaxed wins!). We travel through your hierarchy, taking time to fully feel the anxiety, but then relaxing your way through it. You do not go to the next level until we have mastered the one before it, and so on. I think you get the picture.
This technique is possible to complete by yourself, but sometimes it is useful to have a professional guide you through it.If you stick with it, you will eventually be able to snap into a relaxed state even when you are faced with the foreboding doctor's office!
Best of luck to you, I wish you well in your pregnancy. If you are satisfied with the response, please hit "Accept." That is the only way I receive credit for my answer. Thanks-