depends, normally it should, but sometimes something can go wrong. my friend projected once, i fogret exactly what happened, but he got into a situation he wanted to get out of asap so he immediately shot back to his body so fast he had to lie there for a good half hour trying to calm down. never projected since, because every time he tries, he begins to leave his body but something subconsciously reminds him about what happened and he quickly returns to him body. it's some fear he has that he needs to overcome.
perhaps what happened was a crash landing into your body. try projecting again, but instead of leaving your room, float around for a bit, then go back into your body. slowly each time you project, move a bit further out, when you want to return however, think of your room, then your body. i normally do that, and i've never awoken in a panic or something. once though i didn't and i was rather soar, so that could of been it, you were zapped back really fast. mind you i'm no expert, could be something else, just what i know though experience.