Yes this is completely normal. Food is such a comfort for lots of people i know, if they're upset, or confused, or scared or w/e it is not uncommon. It is simply another coping mechanism, but like too much of anything, it can become unhealthy if you overeat too much. If it isn't happening alot of the time, then i wouldn't worry about it. If it is, well maybe there are other ways things that you can find comfort in as a replacement. Some people find comfort in reading a good book, listening to favourite music, watching movies, writing in a journal, talking to a friend, there are many things that you can do.
Hope this helps ...