Yes it is normal to have those feeling and I can not say once you go into labor they will go out the window. For most woman those fears go away once they are in labor. About defecating it is possible you will, however there a couple of things you can do to help that from happening. One is to have an enema when you first go into labor. That will clear you out before you feel the need to push. Another thing is to make sure you try to go to the bathroom as much as possible before you get to the point where you can not get to the bathroom on your own. You can request that only the doc and as little as possible people other then yourself be in the room when you deliver. If you can afford to hire a Doula she can help be your voice when you are in labor so you can have the birth you want with the privacy you want.

I'm both pregnant and I work in the OR, (well I'm not working at this point because I had to stop due to pre-term contractions, I'm now 37weeks), and I can assure you that no one will be paying attention to the fact that your naked and almost all women defecate while in labor, and no one will be paying attention to that either. It's a normal part of labor. When I was working I saw naked people several times a day and looking at a vagina is no different than looking at an arm for us. Don't worry about it! I'm willing to bet that those will be the last things on your mind in the midst of things! Try to relax and when you get anxiety, just think of how wonderful it's going to be to see your beautiful baby! Good Luck!