What you are feeling is normal, and anyone in that situation would always assume the worst. The same thing happened to me last month. Well not the exact same thing, but ya know. If you took only half of your whole months worth of pills, and a few days to a week after you had some sort of bleeding going on down there, then I would say that you are fine. It was too close in time for you to have a full period again, and your cycle is probably really screwed up now. If you have been on the pills for a few years without ever stopping then I think you are fine. Your cycle doesnt really know what to do because you took some pills but didnt take 28 days worth, and the fact that you are stressed could be holding it off. If you were pregnant I think it would definately show up in a test now. I'm glad that you made an appoitment just to be on the safe side. If it happens again call your doctor and ask them to write you a prescription, then just start where you left off. I hope that everything works out and you are ok.
P.S-- you should think about switching to the patch, its the best thing since sliced bread, I love it!!! Its so easy you dont have to worry about taking a pill everyday or losing your pills!!!