Roommates- Take One! Action!

I have always lived with family. That is until this past October. My mother who is disabled needs someone able bodied to live with her. This had always been me since I was the last chick to leave the nest. However, in the last year it came to pass that my older brother was thinking about moving back home. I took this as the chance that I had been longing for and moved out.
I was lucky enough to have a friend who had just purchased her first house and was looking for someone to rent to. I have known J (my roommate) for about 8 years now. We have been friends for about 6. I was not overly worried about living with her in regards to her having late parties while I was sleeping, bringing strange men around, being messy, or being just obnoxious. I had known her long enough that I was aware of some of her habits, traits, morals and goals. A lot of these were the same as mine so I figured we would get along better than most.
We moved into the house in October of 2013, and as someone who has NEVER lived with a roommate before I am here to tell you that adjusting to someone completely new is very interesting. I find myself censoring myself as I don't want to upset her or get kicked out of the house! I know J would never actually do this unless I was causing major problems, but I have yet to be 100% myself around her while we have been roommates.
I have an awful habit. My mother was always telling me that I would regret developing this habit and the day has come. My horrible habit is that I tend to belch...loudly. REALLY loud! Like attract attention loud. I have not done this since October! I am embarrassed by this habit and do not do it in front of my new roommate for fear of grossing her out!
Now remember, I have known J for over 6 years. Chances are very high that I have belched in front of her before in the last 6-8 years, however she did not have to live with me at the time.
Am I being silly by not just being myself all of the time? My mother would tell me that I should feel free to be myself but that belching is not a bad habit to lose. What do you think? Are there certain friends or people in your life that you find yourself censoring yourself around?